Predictive medicine

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Predictive_medicine 

Predictive medicine is a field of medicine that entails predicting the probability of disease and instituting preventive measures in order to either prevent the disease altogether or significantly decrease its impact upon the patient (such as by preventing mortality or limiting morbidity).

While different prediction methodologies exist, such as genomics, proteomics, and cytomics, the most fundamental way to predict future disease is based on genetics. Although proteomics and cytomics allow for the early detection of disease, much of the time those detect biological markers that exist because a disease process has already started. However, comprehensive genetic testing (such as through the use of DNA arrays or full genome sequencing) allows for the estimation of disease risk years to decades before any disease even exists, or even whether a healthy fetus is at higher risk for developing a disease in adolescence or adulthood. Individuals who are more susceptible to disease in the future can be offered lifestyle advice or medication with the aim of preventing the predicted illness.

Current genetic testing guidelines supported by the health care professionals discourage purely predictive genetic testing of minors until they are competent to understand the relevancy of genetic screening so as to allow them to participate in the decision about whether or not it is appropriate for them. Genetic screening of newborns and children in the field of predictive medicine is deemed appropriate if there is a compelling clinical reason to do so, such as the availability of prevention or treatment as a child that would prevent future disease.

The goal

The goal of predictive medicine is to predict the probability of future disease so that health care professionals and the patient themselves can be proactive in instituting lifestyle modifications and increased physician surveillance, such as bi-annual full body skin exams by a dermatologist or internist if their patient is found to have an increased risk of melanoma, an EKG and cardiology examination by a cardiologist if a patient is found to be at increased risk for a cardiac arrhythmia or alternating MRIs or mammograms every six months if a patient is found to be at increased risk for breast cancer. Predictive medicine is intended for both healthy individuals ("predictive health") and for those with diseases ("predictive medicine"), its purpose being to predict susceptibility to a particular disease and to predict progression and treatment response for a given disease.

A number of association studies have been published in scientific literature that show associations between specific genetic variants in a person's genetic code and a specific disease. Association and correlation studies have found that a female individual with a mutation in the BRCA1 gene has a 65% cumulative risk of breast cancer. Additionally, new tests from Genetic Technologies LTD and Phenogen Sciences Inc. comparing non-coding DNA to a woman's lifetime exposure to estrogen can now determine a woman's probability of developing estrogen positive breast cancer also known as sporadic breast cancer (the most prevalent form of breast cancer). Genetic variants in the Factor V gene is associated with an increased tendency to form blood clots, such as deep vein thrombosis (DVTs). Genetics tests are expected to reach the market more quickly than new medicines. Myriad Genetics is already generating revenue from genetic tests for BRCA1 and BRCA2.

Aside from genetic testing, predictive medicine utilizes a wide variety of tools to predict health and disease, including assessments of exercise, nutrition, spirituality, quality of life, and so on. This integrative approach was adopted when Emory University and Georgia Institute of Technology partnered to launch the Predictive Health Institute. Predictive medicine changes the paradigm of medicine from being reactive to being proactive and has the potential to significantly extend the duration of health and to decrease the incidence, prevalence and cost of diseases.

Types

Notable types of predictive medicine through health care professionals include:

• Carrier testing: Carrier testing is done to identify people who carry one copy of a gene mutation that, when present in both copies, causes a genetic disorder. This type of testing is offered to individuals who have genetic disorder in their family history or to people in ethnic groups with increased risk of certain genetic diseases. If both parents are tested, carrier testing can provide information about a couple's risk of having a child with a genetic disorder.
• Diagnostic testing: Diagnostic testing is conducted to aid in the specificity diagnosis or detection of a disease. It is often used to confirm a particular diagnosis when a certain condition is suspected based on the subject's mutations and physical symptoms. The diversity in diagnostic testing ranges from common consulting room tests such as measuring blood pressure and urine tests to more invasive protocols such as biopsies.
• Newborn screening: Newborn screening is conducted just after birth to identify genetic disorders that can be treated early in life. This testing of infants for certain disorders is one of the most widespread uses of genetic screening - all US states currently test infants for phenylketonuria and congenital hypothyroidism. US state law mandates collecting a sample by pricking the heel of a newborn baby to obtain enough blood to fill a few circles on filter paper labeled with names of infant, parent, hospital, and primary physician.
• Prenatal testing: Prenatal testing is used to look for diseases and conditions in a fetus or embryo before it is born. This type of testing is offered for couples who have an increased risk of having a baby with a genetic or chromosomal disorder. Screening can determine the sex of the fetus. Prenatal testing can help a couple decide whether to abort the pregnancy. Like diagnostic testing, prenatal testing can be noninvasive or invasive. Non-invasive techniques include examinations of the woman's womb through ultrasonography or maternal serum screens. These non-invasive techniques can evaluate risk of a condition, but cannot determine with certainty if the fetus has a condition. More invasive prenatal methods are slightly more risky for the fetus and involve needles or probes being inserted into the placenta or chorionic villus sampling.

Health benefits

The future of medicine's focus may potentially shift from treating existing diseases, typically late in their progression, to preventing disease before it sets in. Predictive health and predictive medicine is based on probabilities: while it evaluates susceptibility to diseases, it is not able to predict with 100% certainty that a specific disease will occur. Unlike many preventive interventions that are directed at groups (e.g., immunization programs), predictive medicine is conducted on an individualized basis. For example, glaucoma is a monogenic disease whose early detection can allow to prevent permanent loss of vision. Predictive medicine is expected to be most effective when applied to polygenic multifactorial disease that are prevalent in industrialized countries, such as diabetes mellitus, hypertension, and myocardial infarction. With careful usage, predictive medicine methods such as genetic screens can help diagnose inherited genetic disease caused by problems with a single gene (such as cystic fibrosis) and help early treatment. Some forms of cancer and heart disease are inherited as single-gene diseases and some people in these high-risk families may also benefit from access to genetic tests. As more and more genes associated with increased susceptibility to certain diseases are reported, predictive medicine becomes more useful.

Direct-to-consumer genetic testing

Direct-to-Consumer (DTC) genetic testing enables a consumer to screen his or her own genes without having to go through a health care professional. They can be ordered without the permission of a physician. Variety in DTC tests range from those testing for mutations associated with cystic fibrosis to breast cancer alleles. DTC tests make the applicability of predictive medicine very real and accessible to consumers. Benefits of DTC testing include this accessibility, privacy of genetic information, and promotion of proactive health care. Risks of obtaining DTC testing are the lack of governmental regulation and the interpreting of genetic information without professional counseling.

Limitations of predictive medicine

On a protein level, structure is less conserved than sequence. Therefore, in many diseases, having the faulty gene still does not necessarily mean someone will get the disease. Common, complex diseases in the wider population are affected not only by heredity, but also by external causes such as lifestyle and environment. Therefore, genes are not perfect predictors of future health; individuals with both the high risk form of the gene and those without are all candidates to get the disease. Multiple factors in the environment, particular smoking, diet and exercise, infection, and pollution; play important roles and can be more important than genetic make-up. This makes the results and risks determined by predictive medicine more difficult to quantify. Furthermore, the potential false positives or false negatives that may arise from a predictive genetic screen can cause substantial unnecessary strain on the individual.

Targeting medication to people who are genetically susceptible to a disease but do not yet show the symptoms of it can be a questionable measure. In large populations, there is concern that likely most of the people taking preventative medications would never have developed the disease anyway. Many medications carry undesirable side effects that high risk individuals must then cope with. In contrast, several populations-based prevention measures (such as encouraging healthy diets or banning tobacco advertising) carry a far lower likelihood of adverse effects and are also less expensive.

Another potential downfall of commercially available genetic testing lies within the psychological impacts of accessibility to such data. For single-gene inherited diseases, counseling and the right to refuse a test (the right "not to know") have been found to be important. However, adequate individual counseling can be difficult to employ to the potentially large proportion of the population likely to be identified as at high risk of common complex disease. Some people are vulnerable to adverse psychological reactions to genetic predictions of stigmatized or feared conditions, such as cancer or mental illness.

Ethics and law

Predictive medicine ushers in a number of sensitive legal and ethical issues. There is a delicate balance that presides over predictive medicine and occupational health: if an employee were dismissed because he was found to be at risk of a certain chemical agent used in his workplace, would his termination be considered discrimination or an act of prevention? Several organizations believe that legislation is needed to prevent insurers and employers from using predictive genetic test results to decide who gets insurance or a job: "Ethical considerations, and legal, are fundamental to the whole issue of genetic testing. The consequences for individuals with regard to insurance and employment are also of the greatest importance, together with the implications for stigma and discrimination." In the future, people may be required to reveal genetic predictions about their health to their employers or insurers. The grim prospect of discrimination based on a person's genetic make-up can lead to a "genetic underclass" which does not receive equal opportunity for insurance and employment.

Currently in the United States, health insurers do not require applicants for coverage to undergo genetic testing. Genetic information is under the same protection of confidentiality as other sensitive health information under the Health Insurance Portability and Accountability Act (HIPAA) when health insurers come across it. In the United States, the Genetic Information Nondiscrimination Act, signed into law by President Bush on May 21, 2008; prohibits health insurers from denying coverage or charging differentials in premiums, and bars employers from making job placement or hiring/firing decisions based on individuals' genetic predispositions.

Genetic counseling

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Genetic_counseling 

Genetic counseling is the process of advising individuals and families affected by or at risk of genetic disorders to help them understand and adapt to the medical, psychological and familial implications of genetic contributions to disease; this field is considered necessary for the implementation of genomic medicine. The process integrates:

• Interpretation of family and medical histories to assess the chance of disease occurrence or recurrence
• Education about inheritance, testing, management, prevention, resources
• Counseling to promote informed choices, adaptation to the risk or condition and support in reaching out to relatives that are also at risk

History

The practice of advising people about inherited traits began around the turn of the 20th century, shortly after William Bateson suggested that the new medical and biological study of heredity be called “genetics”. Heredity became intertwined with social reforms when the field of modern eugenics took form. Although initially well-intentioned, ultimately the movement had disastrous consequences; many states in the United States had laws mandating the sterilization of certain individuals, others were not allowed to immigrate and by the 1930s these ideas were accepted by many other countries including in Germany where euthanasia for the “genetically defective” was legalized in 1939. This part of the history of genetics is at the heart of the now “non directive” approach to genetic counseling.

Sheldon Clark Reed coined the term genetic counseling in 1947 and published the book Counseling in Medical Genetics in 1955. Most of the early genetic counseling clinics were run by non-medical scientists or by those who were not experienced clinicians. With the growth in knowledge of genetic disorders and the appearance of medical genetics as a distinct specialty in the 1960s, genetic counseling progressively became medicalized, representing one of the key components of clinical genetics. It was not, though, until later that the importance of a firm psychological basis was recognized and became an essential part of genetic counseling, the writings of Seymour Kessler making a particular contribution to this. The first master's degree genetic counseling program in the United States was founded in 1969 at Sarah Lawrence College in Bronxville, New York. In 1979, the National Society of Genetic Counselors (NSGC) was founded and led by the first president, Audrey Heimler.

Professional roles

Genetic counselors work in a wide variety of patient-facing and non patient-facing settings. Clinical genetic counselors may provide general care, or specialize in one or more areas.

Examples include:

• Prenatal and pre-conception – for women and their partners who are pregnant or thinking about becoming pregnant
• Pediatric – for children with genetic, or suspected genetic, conditions and their family members
• Cancer – for patients with cancer and/or their family members
• Cardiovascular – for patients with diseases of the heart or circulatory system and/or their family members
• Neurology – for patients with diseases of the brain and nervous system and/or their family members
• Assisted reproductive technology / infertility – for couples struggling with fertility or who are carriers of genetic diseases
• Psychiatric – for patients living with mental illness and/or their family members

Outside the clinic, genetic counselors work in areas such as laboratories, research, education, public health settings, and corporate environments. Examples of roles include:

• Laboratory – Utilization management, provider and patient support, variant classification, and reporting
• Research – Coordinating research studies, patient recruitment, data collection and interpretation, manuscript preparation and grant writing
• Education – Professors, directors of genetic counseling training programs
• Public health – Newborn screening programs, population screening programs
• Non-profit – Patient support and advocacy organizations
• Corporate – Dedicated services for employees and their families

Detection and early processes

Diagnostic testing occurs when an individual is showing signs or symptoms associated with a specific condition. Genetic testing can be used to arrive at a definitive diagnosis in order to provide better prognosis as well as medical management and/or treatment options. Testing can reveal conditions can be mild or asymptomatic with early treatment, as oppose to debilitating without treatment (such as phenylketonuria). Genetic tests are available for a number of genetic conditions, including but not limited to: Down syndrome, sickle cell disease, Tay–Sachs disease, muscular dystrophy. Establishing a genetic diagnosis can provide information to other at-risk individuals in the family.

Any reproductive risks (e.g. a chance to have a child with the same diagnosis) can also be explored after a diagnosis. Many disorders cannot occur unless both the mother and father pass on their genes, such as cystic fibrosis; this is known as autosomal recessive inheritance. Other autosomal dominant diseases can be inherited from one parent, such as Huntington disease and DiGeorge syndrome. Yet other genetic disorders are caused by an error or mutation occurring during the cell division process (e.g. aneuploidy) and are not hereditary.

Screening tests are often used prior to diagnostic testing, designed to separate people according to a fixed characteristic or property, with the intention of detecting early evidence of disease. For example, if a screening test during a pregnancy (such as maternal blood screening or ultrasound) reveals a risk of a health issue or genetic condition, patients are encouraged to receive genetic counseling to learn additional information regarding the suspected condition. A discussion of the management, therapy and treatments available for the conditions may take place; the next step may differ depending on the severity of the condition and range from during pregnancy to after delivery. Patients may decline additional screening and testing, elect to proceed to diagnostic testing, or pursue further screening tests to refine the risk during the pregnancy.

Presymptomatic or predictive testing occurs when an individual knows of a specific diagnosis (typically adult onset) in their family and has other affected relatives, but they themselves do not manifest any clinical findings at the time when they seek testing. The decision about whether or not to proceed with presymptomatic testing should entail a thoughtful approach and consideration of various medical, reproductive, social, insurance, and financial factors, with no “right” or “wrong” answer. Availability of treatment and medical management options for each specific diagnosis, as well as the genetics and inheritance pattern of the particular condition should be reviewed as inherited conditions can have reduced penetrance.

Insurance and legal issues should also be discussed during genetic counseling. There are laws in the United States such as GINA (Genetic Information Non-discrimination Act) and ACA that provide certain protections against discrimination for individuals with genetic diagnoses.

Approach and session overview

Approach

There are different approaches to genetic counseling. The reciprocal-engagement model of genetic counseling practice includes tenets, goals, strategies, and behaviors for addressing patients' genetic concerns. Some counselors favor a psycho-educational approach while others incorporate more psycho-therapeutic techniques. Genetic counseling is psycho-educational as patients "learn how genetics contributes to their health risks and then process what this means and how it feels."

Whether the process of genetic counseling is a form of psychotherapy is up for debate. The relationship between the client and counselor is similar as are the goals of the sessions. As a psychotherapist aims to help his client improve his wellbeing, a genetic counselor also helps his client to address a "situational health threat that similarly threatens client wellbeing". Due to the lack of studies which compare genetic counseling to the practice of psychotherapy, it is hard to say with certainty whether genetic counseling can be "conceptualized as a short-term, applied, specific type of psychotherapy". However, there few existing studies suggest that genetic counseling falls "significantly short of psychotherapeutic counseling" because genetic counseling sessions primarily consist of the distribution of information without much emphasis placed on explaining any long-term impacts to the client.

Structure

The goals of genetic counseling are to increase understanding of genetic diseases, discuss disease management options and explain the risks and benefits of testing. Counseling sessions focus on giving vital, unbiased information and non-directive assistance in the patient's decision-making process. Seymour Kessler, in 1979, first categorized sessions in five phases: an intake phase, an initial contact phase, the encounter phase, the summary phase, and a follow-up phase. The intake and follow-up phases occur outside of the actual counseling session. The initial contact phase is when the counselor and families meet and build rapport. The encounter phase includes dialogue between the counselor and the client about the nature of screening and diagnostic tests. The summary phase provides all the options and decisions available for the next step. If patients wish to go ahead with testing, an appointment is organized and the genetic counselor acts as the person to communicate the results. Result delivery can happen both in person or via phone. Often counselors will call out results to avoid patients having to come back in as results can take weeks to be processed. If further counseling is needed in a more personal setting, or it is determined that additional family members should be tested, a secondary appointment can be made.

Support

Genetic counselors provide supportive counseling to families, serve as patient advocates and refer individuals and families to community or state support services. They serve as educators and resource people for other health care professionals and for the general public. Many engage in research activities related to the field of medical genetics and genetic counseling. When communicating increased risk, counselors anticipate the likely distress and prepare patients for the results. Counselors help clients cope with and adapt to the emotional, psychological, medical, social, and economic consequences of the test results.

Each individual considers their family needs, social setting, cultural background, and religious beliefs when interpreting their risk. Clients must evaluate their reasoning to continue with testing at all. Counselors are present to put all the possibilities in perspective and encourage clients to take time to think about their decision. When a risk is found, counselors frequently reassure parents that they were not responsible for the result. An informed choice without pressure or coercion is made when all relevant information has been given and understood.

After counseling for other hereditary conditions, the patient may be presented with the option of having genetic testing. In some circumstances no genetic testing is indicated, other times it may be useful to begin the testing process with an affected family member. The genetic counselor also reviews the advantages and disadvantages of genetic testing with the patient.

Outcomes

The most commonly measured genetic counseling outcomes included knowledge, anxiety or distress, satisfaction, perceived risk, genetic testing (intentions or receipt), health behaviors, and decisional conflict. Results suggest that genetic counseling can lead to increased knowledge, perceived personal control, positive health behaviors, and improved risk perception accuracy as well as decreases in anxiety, cancer-related worry, and decisional conflict.

Sub-specialties

Adult genetics

Adult or general genetics clinics serve patients who are diagnosed with genetic conditions that begin to show signs or symptoms in adulthood. Many genetic conditions have varying ages of onset, ranging from an infantile form to an adult form. Genetic counseling can facilitate the decision making process by providing the patient/family with education about the genetic condition as well as the medical management options available to individuals at risk of developing the condition. Having the genetic information of other members of the family opens the door to asking important questions about the pattern of inheritance of specific disease‐causing mutations. Whilst there is a wealth of literature that describes how families communicate information surrounding single genes, there is very little which explores the experience of communication about family genomes. Adult-onset disorders may overlap multiple specialties.

ART/Infertility genetics

Genetic counseling is an integral part of the process for patients utilizing preimplantation genetic testing (PGT), formerly called preimplantation genetic diagnosis. There are three types of PGT and all require in vitro fertilization (IVF) using assisted reproductive technology (ART). PGT-M, for monogenic disorders, involves testing embryos for a specific condition before it is implanted into the mother. This technique is currently being done for disorders with childhood onset, such as Cystic Fibrosis, Tay-Sachs and Muscular Dystrophy, as well as adult-onset conditions, including Huntington's Disease, Hereditary Breast and Ovarian Cancer Syndrome, and Lynch Syndrome. PGT-SR, for structural rearrangements, involves testing embryos to establish a pregnancy unaffected by a structural chromosomal abnormality (translocation). PGT-A, for aneuploidy, was formerly called preimplantation genetic screening, and involved testing embryos to identify any de novo aneuploidy. The indications to carry out PGT-A are: previous aneuploidy in the couple, implantation failure, recurrent miscarriage, severe male factor or advanced maternal age. Finally, PGT seems to be: safe for the embryo, trustable in the diagnosis, more efficient from the reproductive point of view and cost-effective.

Genetic counseling can also involve medical evaluation and clinical work-up for couples with infertility and/or recurrent pregnancy loss, as these histories can be associated with parental chromosome aberrations (such as inversions or translocations) and other genetic conditions.

Cardiovascular genetics

A rapidly expanding field in genetic counseling is cardiovascular genetics. More than 1 in 200 people have an inherited cardiovascular disease. Hereditary cardiac conditions range from common diseases, such as high cholesterol and coronary artery disease, to rare diseases like Long QT Syndrome, hypertrophic cardiomyopathy, and vascular diseases.  Genetic counselors who specialize in cardiovascular disease have developed skills specific to the management of and counseling for genetic cardiovascular disorders and practice in both the pediatric and adult setting. Cardiovascular genetic counselors are also integral in local and national efforts to prevent sudden cardiac death, which is the leading cause of sudden death in young people. This is done by identifying patients with known or suspected heritable cardiovascular diseases and promoting cascade family screening or testing of at-risk relatives.

Common referral reasons include:

• Cardiomyopathy, including, hypertrophic cardiomyopathy and familial idiopathic dilated cardiomyopathy
• Arrhythmia, including Long QT syndrome and Brugada syndrome
• Vascular disease, including Marfan syndrome and aortic aneurysm and/or dissection (<50 years old)
• Congenital heart defects (e.g. conotruncal defects, left ventricular outflow tract defects)
• Familial hypercholesterolemia
• Family history of unexplained sudden death

Guidelines on cardiovascular genetics are published by multiple professional societies.

Hereditary cancer genetics

Cancer genetic counselors see individuals with a personal diagnosis and/or family history of cancer or symptoms of an inherited cancer syndrome. Genetic counselors take a family history and assess for hereditary risk, or risk that can be passed down from generation to generation. If indicated, they can coordinate genetic testing, typically via blood or saliva sample, to evaluate for hereditary cancer risk.  Personalized medical management and cancer screening recommendations can be provided based on results of genetic testing and/or the family history of cancer. While most cancers are sporadic (not inherited), some are more likely to have a hereditary factor, particularly when occurring at young ages or when clustering in families. These include common cancers such as breast, ovarian, colon and uterine cancers, as well as rare tumor types. General referral indications can include, but are not limited to:

• Personal or family history of cancer with unusually young age of onset (e.g. breast cancer under age 45, colon cancer under age 50)
• Diagnosis of a tumor or cancer with a high likelihood to be hereditary (e.g. male breast cancer, triple negative breast cancer, ovarian cancer, metastatic or high-grade prostate cancer, pancreatic cancer, retinoblastoma, adrenocortical carcinoma, pleuropulmonary blastoma, neuroendocrine tumor, medullary thyroid cancer, pheochromocytoma or paraganglioma)
• Personal or family history of bilateral cancers (e.g., both breasts or both kidneys) or multiple primary tumors in one person
• Features associated with an inherited cancer syndrome (e.g. more than 10 adenomatous polyps, rare types of gastrointestinal polyps, such as hamartomatous polyps), or specific skin findings like café au lait macules or freckling on the lips
• Family history of related cancers clustered on the same side of the family (e.g. breast/ovarian, colon/uterine, sarcoma/leukemia/brain)
• Family history of a known inherited cancer syndrome (e.g. hereditary breast and ovarian cancer syndrome, hereditary non-polyposis colorectal cancer, Li-Fraumeni syndrome)
• Individuals of Ashkenazi Jewish ancestry with a personal and/or family history of breast, ovarian, or pancreatic cancer
• Possible germline (inherited) genetic mutation suggested by tumor profile testing

Neurogenetics

Genetic counselors specializing in neurogenetics are involved in the care of individuals who have or are at risk to develop conditions affecting the central nervous system (brain and spinal cord) or peripheral nervous system (the nerves that leave the spinal cord and go to other places in the body, such as the feet and hands, skeletal muscles, and internal organs). Effects of these conditions can lead to various impairments some examples of which include cognitive decline, intellectual disability, seizures, uncontrolled movements (e.g. ataxia, chorea), muscle weakness, paralysis, or atrophy. Examples of neurogenetic disorders include:

• Brain malformation syndromes, including lissencephaly and polymicrogyria
• Brain tumor predisposition syndromes, including Neurofibromatosis 1 and 2
• Epilepsy (seizures)
• Hereditary motor neuron diseases, including amyotrophic lateral sclerosis (ALS/Lou Gehrig's disease) and spinal muscular atrophy
• Hereditary neuropathies, including Charcot-Marie-Tooth disease
• Intellectual disabilities, developmental delays, and autism spectrum disorder
• Leukodystrophy (hereditary white matter diseases)
• Memory and other cognitive disorders, including Alzheimer disease and frontotemporal dementia
• Movement disorders, including hereditary ataxia, spastic paraplegia, Huntington disease, and Parkinson disease
• Neuromuscular disorders, including muscular dystrophies, congenital myopathies, and congenital myasthenic syndromes

Pediatric genetics

Pediatric genetic counseling can be indicated for newborns, infants, children and their families. General referral indications can include:  

• Birth defect(s) or multiple congenital anomalies (cleft lip/palate, heart defects, spina bifida)
• Intellectual disability of unknown cause, learning disabilities, or autism
• Sensory impairments (vision, hearing)
• Metabolic disorders (PKU, galactosemia)
• Known/Suspected genetic disorders (e.g., Down syndrome, Cystic Fibrosis, Muscular Dystrophy)

Prenatal genetics

Prenatal genetics involves services for women either during or prior to a pregnancy.

General indications for referral to genetic counseling in the preconception or prenatal setting may include, but are not limited to:

• Advanced maternal age (35 years old or older at time of delivery)
• Advanced paternal age
• Current pregnancy with anomalies identified by ultrasound (e.g. increased nuchal translucency measurements)
• Current pregnancy with an abnormal genetic screening test or test result
• Current pregnancy with risk of or concern for maternal exposures, such as medications, radiation, drugs/alcohol, or infections
• Consanguineous union (cousins or otherwise blood related)
• Family history of an inherited genetic condition or chromosome abnormality
• Genetic carrier screening for recessive and/or X-linked diseases
• History of a previous child with a birth defect, developmental delay, or other genetic condition
• History of infertility, multiple unexplained miscarriages or cases of unexplained infant deaths
• Molecular test for single gene disorder

Prenatal genetic counseling may help with the decision-making process by walking patients through examples of what some people might do in similar situations, and their rationale for choosing that option. Decisions made by patients are affected by factors including timing, accuracy of information provided by tests, and risk and benefits of the tests. This discussion enables patients to place the information and circumstances into the context of their own lives, and in the context of their own values. They may choose to undergo noninvasive screening (e.g. ultrasound, triple screen, cell-free fetal DNA screening) or invasive diagnostic testing (amniocentesis or chorionic villus sampling). Invasive diagnostic tests possess a small risk of miscarriage (1–2%) but provide more definitive results. Testing is offered to provide a definitive answer regarding the presence of a certain genetic condition or chromosomal abnormality.

Psychiatric genetics

Psychiatric genetic counseling is a sub-specialty within genetic counseling focused on helping people living with a psychiatric disorder and/or their family members understand both the genetic and environmental factors that contributed to their illness and address associated emotions such as guilt or self-blame. Genetic counselors also discuss strategies to promote recovery and protect mental health and address any questions on chances for recurrence in other family members. While currently there is no single gene solely responsible for causing a psychiatric disorder, there is strong evidence from family, twin studies, and genome-wide-association studies that both multiple genes and environment interact together. Like other areas of genetic counseling, patients at all different stages of life (pediatric, adult, prenatal) can have psychiatric genetic counseling. Since the etiology of psychiatric disorders is complex and not fully understood, the utility of genetic testing is not as clear as it is in Mendelian or single gene disorders. Research has shown that individuals who receive psychiatric genetic counseling have significant increases in feelings of empowerment and self-efficacy after genetic counseling.

Psychiatric genetic counselors can help "dispel mistaken notions about psychiatric disorders, calm needless anxiety, and help those at risk to draw up a rational plan of action based on the best available information".

International

In 2018, there are nearly 7000 genetic counselors practicing worldwide, across at least 28 countries.

China

Genetic counseling in China (mainland) has been primarily provided by pediatricians or obstetricians for prenatal or birth defect diagnoses. Most genetic tests can only be performed in academic institutions as research tests or in commercial direct-to-consumer companies for non-clinical use.

In China, genetic counseling is steered by the Chinese Board of Genetic Counseling (CBGC), a not-for-profit organization. CBGC is composed of senior experts engaged in genetic education and research. CBGC is committed to establishing standardized procedures of genetic counseling, training qualified genetic counselors, improving health for all, and reducing the incidence of birth defects. CBGC was established in 2015 and is the major professional organization for genetic counselors in mainland China, providing training through short term online and in-person lectures, educational conferences, and certification for trainees.    

Genetics education in China began in the 1980s when selected medical schools began offering genetics courses that focused predominantly on molecular genetics and had limited clinical content. At present, there are no official master's level graduate programs in genetic counseling or clinical genetics in China, and there is great variability in the duration and content of genetics curricula among medical schools and professional organizations.

The Chinese Ministry of Health has not yet recognized genetic counselors as an independent health care occupation. There are no official statistics for the number of health care professionals (e.g., physicians, nurses, and lab technicians) who are providing genetic counseling services in China.

South Africa

Genetic Counselling is a developing field in South Africa. Currently, there are about 20 registered genetic counsellors practicing in the country. In South Africa, genetic counsellors work within academic institutions, in the private health sector and more recently, private genetic laboratories. A few qualified genetic counsellors have been employed outside of the country or in other professions, owing to funding limitations that have impacted employment opportunities, particularly in the academic/public health sector.

The first Genetic Counselling Programme in South Africa started in 1989 at the University of the Witwatersrand in Johannesburg, in the Gauteng province. A second programme started in 2004 at the University of Cape Town in the Western Cape province. These are the only two programmes offering Masters level genetic counselling training in South Africa. Currently these courses are running at full capacity.  This is a two-year degree and includes a research component. The majority of students enter the Masters programme with a science background but those with a psychology background are also be considered.

The Health Professions Council of South Africa (HPCSA) requires two years of internship. Often the first year forms part of the master's degree in Genetic Counselling and a further 12-month internship thereafter. Genetic Counsellors are required by law to register with the HPCSA in order to practice as genetic counsellors. At the end of the training period, registrants submit a portfolio to HPCSA for assessment. If successful, the intern will be registered with the HPCSA and will be able to practice as a Genetic Counsellor in South Africa.

There is a professional organisation for Genetic Counsellors in South Africa, Genetic Counselling South Africa (GC-SA), which provides information and guidance to the HPCSA and others regarding professional issues. The GCSA is a focus group of the South African Society of Human Genetics (SASHG).

United Kingdom

The majority of Genetic Counsellors in the UK work in the National Health Service (NHS) in one of the 33 Regional Clinical Genetics Services (some renamed Genomic Medicine Centres in England), Scotland, Wales or Northern Ireland. Others work in specialist roles in the NHS, education, policy or research. A minority work in the private sector.

The Association of Genetic Nurses and Counsellors (AGNC) is the UK's professional organization representing genetic counsellors, genetic nurses and non-medical, patient-facing staff working within the discipline of Clinical Genetics. There are currently (March 2018) 330 AGNC members within the UK. The AGNC is one of the constituent groups of the British Society for Genetic Medicine (BSGM).

The first 2-year MSc in Genetic Counselling program established in the UK was from the University of Manchester 1992, followed by Cardiff University in Wales in 2000. 2016 saw major changes in the way genetic counsellors are trained in England. A 3-year training programme funded by Health Education England, the Scientist Training Programme (STP) uses a combination of work-based training in Genomic Medicine Centres and a part-time MSc in Genetics (Genomic Counselling) from the University of Manchester. Recruitment is performed nationally through the National School of Healthcare Science (NSHCS). A 3-year part-time MSc in Genetic and Genomic Counselling is also now delivered by Cardiff University, through blended learning, with most of the teaching delivered online, alongside some short face-to-face teaching blocks in Wales. A 2-year MSc Genetic and Genomic Counselling program began at the University of Glasgow in Scotland in 2016. Prerequisites for acceptance on all the programmes include a degree in a relevant science or a nursing or midwifery qualification, and experience in a caring role.  All genetic counselling training programmes are accredited by the UK Genetic Counsellor Registration Board (GCRB) and the European Board of Medical Genetics (EBMG).

Genetic counsellors in the UK are regulated through the Genetic Counsellor Registration Board (GCRB), although currently GCRB registration is voluntary. The GCRB registry was accredited in 2016 by the Professional Standards Authority under its Accredited Registers programme. Over 200 genetic counsellors are currently registered through the GCRB. Genetic Counsellors trained through the STP programme are expected to be eligible to apply for statutory regulation through the Health Care Professions Council and it is planned that soon there will be equivalence arrangements with the GCRB to ensure statutory regulation for GCRB registered genetic counsellors.

United States

Education

A genetic counselor is an expert with a Master of Science degree in genetic counseling. Programs in North America are accredited by the Accreditation Council for Genetic Counseling (ACGC). There are currently 48 accredited programs in the United States, four accredited programs in Canada, and four programs with the intent to become accredited. Students enter the field from a variety of disciplines, including biology/biological sciences and social sciences such as psychology. Graduate school coursework includes topics such as human genetics, embryology, ethics, research, and counseling theory and techniques. Clinical training including supervised rotations in prenatal, pediatric, adult, cancer, and other subspecialty clinics, as well as non-patient facing rotations in laboratories. Research training typically culminates in a capstone or thesis project.

State licensure

As of May 2019, 29 states have passed genetic counselor licensure bills that require genetic counselors to meet a certain set of standards to practice. These states are Alabama, Arkansas, California, Connecticut, Delaware, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kentucky, Louisiana, Massachusetts, Michigan, Minnesota, Nebraska, New Hampshire, New Jersey, New Mexico, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Tennessee, Utah, Virginia, and Washington. Almost every other state in the United States is in the process of obtaining genetic counseling licensure.

Although genetic counseling has been established over four decades, the first licenses for genetic counselors were not issued until 2002. Utah was the first state to do so. The American Society of Human Genetics (ASHG) has since encouraged more states to license genetic counselors before they are allowed to practice. ASHG argues that requiring practitioners to go through the necessary training and testing to obtain a license will ensure quality genetic services as well as allow for reimbursement for counselors’ services. Laws requiring licensure ensure that "professionals who call themselves genetic counselors are able to properly explain complicated test results that could confuse patients and families making important health decisions".

Reimbursement and recognition

Insurance companies usually do not reimburse for unlicensed genetic counselors’ services. Patients who may benefit from genetic counseling may not be able to afford the service due to the expensive out-of-pocket cost. In addition, licensure allows genetic counselors to be searchable in most insurance companies’ databases which gives genetic counselors increased opportunities for earning revenue and clients the opportunity to see "the level of coverage insurers provide for their services".

The Center for Medicare and Medicaid Services (CMS) does not currently recognize genetic counselors as healthcare providers and therefore does not reimburse for genetic counseling services unless they are provided by a physician or nurse practitioner. On June 12, 2019, H.R. 3235 "Access to Genetic Counselor Services Act of 2019," was introduced to the U.S. House of Representatives by U.S. Rep. Dave Loebsack (D-Iowa) and U.S. Rep. Mike Kelly (R-Pennsylvania). H.R. 3235 would authorize CMS to recognize certified genetic counselors as healthcare providers and to cover services furnished by genetic counselors under part B of the Medicare program. Genetic counselors are those licensed by states as such, or, for those in states without licensure, the Secretary of Health and Human Services will set criteria through regulation (likely ABGC certification). Genetic counselors would be paid at 85% of the physician fee schedule. Other providers currently providing genetic counseling services will not be affected by the bill.

Job Outlook

As genetic counseling continues to grow as a branch in the medical field, employment rates of genetic counselors are expected to grow by 21% over the next decade; this statistic suggests that approximately 600 new jobs will become available in the US over this time period. Graduating from an accredited program with a passing score on the board certification exam increases the job prospect. As of May 2019 the median annual wage for genetic counselors was $81,880; the lowest 10% earning less than $61,310 and the highest 10% earning more than $114,750. This includes the varying industries in this field, such as medial and diagnostic laboratories, offices of physicians, hospitals, and colleges/universities.

Media

The National Society of Genetic Counselors (NSGC) blog provides information about current topics in genetic testing and genetic counseling.

Public attitude

Many studies have examined the attitudes of the lay public toward genetic counseling and genetic testing. Barriers to obtaining genetic counseling include lack of understanding of genetics by both patients and healthcare providers, concerns about cost and insurance, and fears of stigma and/or discrimination.

No simple correlation has been found between the change in technology to the changes in values and beliefs towards genetic testing.

Health disparities

An increase in genetic counseling outreach efforts are needed to intentionally extend opportunities to populations that have been historically underrepresented in the profession to create a more diverse and inclusive workforce and access to services. Given the history of low engagement of under-represented minority populations in both clinical genetic services and genetic research, both of these aspects will be challenged and must be addressed before the benefits of precision medicine will be fully realized.

Genetic testing

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Genetic_testing 

Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting, genetic testing can be used to diagnose or rule out suspected genetic disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's genetic makeup. Genetic testing can also be used to determine biological relatives, such as a child's parentage (genetic mother and father) through DNA paternity testing, or be used to broadly predict an individual's ancestry. Genetic testing of plants and animals can be used for similar reasons as in humans (e.g. to assess relatedness/ancestry or predict/diagnose genetic disorders), to gain information used for selective breeding, or for efforts to boost genetic diversity in endangered populations.

The variety of genetic tests has expanded throughout the years. Early forms of genetic testing which began in the 1950s involved counting the number of chromosomes per cell. Deviations from the expected number of chromosomes (46 in humans) could lead to a diagnosis of certain genetic conditions such as trisomy 21 (Down syndrome) or monosomy X (Turner syndrome). In the 1970s, a method to stain specific regions of chromosomes, called chromosome banding, was developed that allowed more detailed analysis of chromosome structure and diagnosis of genetic disorders that involved large structural rearrangements. In addition to analyzing whole chromosomes (cytogenetics), genetic testing has expanded to include the fields of molecular genetics and genomics which can identify changes at the level of individual genes, parts of genes, or even single nucleotide "letters" of DNA sequence.

According to the National Institutes of Health, there are tests available for more than 2,000 genetic conditions, and one study estimated that as of 2017 there were more than 75,000 genetic tests on the market.

Types

Genetic testing is "the analysis of chromosomes (DNA), proteins, and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes, or karyotypes for clinical purposes." It can provide information about a person's genes and chromosomes throughout life.

There are a number of types of testing available, including:

• Cell-free fetal DNA (cffDNA) testing - a non-invasive (for the fetus) test. It is performed on a sample of venous blood from the mother, and can provide information about the fetus early in pregnancy. As of 2015 it is the most sensitive and specific screening test for Down syndrome.
• Newborn screening - used just after birth to identify genetic disorders that can be treated early in life. A blood sample is collected with a heel prick from the newborn 24–48 hours after birth and sent to the lab for analysis. In the United States, newborn screening procedure varies state by state, but all states by law test for at least 21 disorders. If abnormal results are obtained, it does not necessarily mean the child has the disorder. Diagnostic tests must follow the initial screening to confirm the disease. The routine testing of infants for certain disorders is the most widespread use of genetic testing—millions of babies are tested each year in the United States. All states currently test infants for phenylketonuria (a genetic disorder that causes mental illness if left untreated) and congenital hypothyroidism (a disorder of the thyroid gland). People with PKU do not have an enzyme needed to process the amino acid phenylalanine, which is responsible for normal growth in children and normal protein use throughout their lifetime. If there is a buildup of too much phenylalanine, brain tissue can be damaged, causing developmental delay. Newborn screening can detect the presence of PKU, allowing children to be placed on special diets to avoid the effects of the disorder.
• Diagnostic testing - used to diagnose or rule out a specific genetic or chromosomal condition. In many cases, genetic testing is used to confirm a diagnosis when a particular condition is suspected based on physical mutations and symptoms. Diagnostic testing can be performed at any time during a person's life, but is not available for all genes or all genetic conditions. The results of a diagnostic test can influence a person's choices about health care and the management of the disease. For example, people with a family history of polycystic kidney disease (PKD) who experience pain or tenderness in their abdomen, blood in their urine, frequent urination, pain in the sides, a urinary tract infection or kidney stones may decide to have their genes tested and the result could confirm the diagnosis of PKD.
• Carrier testing - used to identify people who carry one copy of a gene mutation that, when present in two copies, causes a genetic disorder. This type of testing is offered to individuals who have a family history of a genetic disorder and to people in ethnic groups with an increased risk of specific genetic conditions. If both parents are tested, the test can provide information about a couple's risk of having a child with a genetic condition like cystic fibrosis.
• Preimplantation genetic diagnosis - performed on human embryos prior to the implantation as part of an in vitro fertilization procedure. Pre-implantation testing is used when individuals try to conceive a child through in vitro fertilization. Eggs from the woman and sperm from the man are removed and fertilized outside the body to create multiple embryos. The embryos are individually screened for abnormalities, and the ones without abnormalities are implanted in the uterus.
• Prenatal diagnosis - used to detect changes in a fetus's genes or chromosomes before birth. This type of testing is offered to couples with an increased risk of having a baby with a genetic or chromosomal disorder. In some cases, prenatal testing can lessen a couple's uncertainty or help them decide whether to abort the pregnancy. It cannot identify all possible inherited disorders and birth defects, however. One method of performing a prenatal genetic test involves an amniocentesis, which removes a sample of fluid from the mother's amniotic sac 15 to 20 or more weeks into pregnancy. The fluid is then tested for chromosomal abnormalities such as Down syndrome (Trisomy 21) and Trisomy 18, which can result in neonatal or fetal death. Test results can be retrieved within 7–14 days after the test is done. This method is 99.4% accurate at detecting and diagnosing fetal chromosome abnormalities. There is a slight risk of miscarriage with this test, about 1:400. Another method of prenatal testing is Chorionic Villus Sampling (CVS). Chorionic villi are projections from the placenta that carry the same genetic makeup as the baby. During this method of prenatal testing, a sample of chorionic villi is removed from the placenta to be tested. This test is performed 10–13 weeks into pregnancy and results are ready 7–14 days after the test was done. Another test using blood taken from the fetal umbilical cord is percutaneous umbilical cord blood sampling.
• Predictive and presymptomatic testing - used to detect gene mutations associated with disorders that appear after birth, often later in life. These tests can be helpful to people who have a family member with a genetic disorder, but who have no features of the disorder themselves at the time of testing. Predictive testing can identify mutations that increase a person's chances of developing disorders with a genetic basis, such as certain types of cancer. For example, an individual with a mutation in BRCA1 has a 65% cumulative risk of breast cancer. Hereditary breast cancer along with ovarian cancer syndrome are caused by gene alterations in the genes BRCA1 and BRCA2. Major cancer types related to mutations in these genes are female breast cancer, ovarian, prostate, pancreatic, and male breast cancer. Li-Fraumeni syndrome is caused by a gene alteration on the gene TP53. Cancer types associated with a mutation on this gene include breast cancer, soft tissue sarcoma, osteosarcoma (bone cancer), leukemia and brain tumors. In the Cowden syndrome there is a mutation on the PTEN gene, causing potential breast, thyroid or endometrial cancer. Presymptomatic testing can determine whether a person will develop a genetic disorder, such as hemochromatosis (an iron overload disorder), before any signs or symptoms appear. The results of predictive and presymptomatic testing can provide information about a person's risk of developing a specific disorder, help with making decisions about medical care and provide a better prognosis.
• Pharmacogenomics - determines the influence of genetic variation on drug response. When a person has a disease or health condition, pharmacogenomics can examine an individual's genetic makeup to determine what medicine and what dosage would be the safest and most beneficial to the patient. In the human population, there are approximately 11 million single nucleotide polymorphisms (SNPs) in people's genomes, making them the most common variations in the human genome. SNPs reveal information about an individual's response to certain drugs. This type of genetic testing can be used for cancer patients undergoing chemotherapy. A sample of the cancer tissue can be sent in for genetic analysis by a specialized lab. After analysis, information retrieved can identify mutations in the tumor which can be used to determine the best treatment option.

Non-diagnostic testing includes:

• Forensic testing - uses DNA sequences to identify an individual for legal purposes. Unlike the tests described above, forensic testing is not used to detect gene mutations associated with disease. This type of testing can identify crime or catastrophe victims, rule out or implicate a crime suspect, or establish biological relationships between people (for example, paternity).
• Paternity testing - uses special DNA markers to identify the same or similar inheritance patterns between related individuals. Based on the fact that we all inherit half of our DNA from the father, and half from the mother, DNA scientists test individuals to find the match of DNA sequences at some highly differential markers to draw the conclusion of relatedness.
• Genealogical DNA test - used to determine ancestry or ethnic heritage for genetic genealogy.
• Research testing - includes finding unknown genes, learning how genes work and advancing understanding of genetic conditions. The results of testing done as part of a research study are usually not available to patients or their healthcare providers.

Medical procedure

Genetic testing is often done as part of a genetic consultation and as of mid-2008 there were more than 1,200 clinically applicable genetic tests available. Once a person decides to proceed with genetic testing, a medical geneticist, genetic counselor, primary care doctor, or specialist can order the test after obtaining informed consent.

Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. For example, a medical procedure called a buccal smear uses a small brush or cotton swab to collect a sample of cells from the inside surface of the cheek. Alternatively, a small amount of saline mouthwash may be swished in the mouth to collect the cells. The sample is sent to a laboratory where technicians look for specific changes in chromosomes, DNA, or proteins, depending on the suspected disorders, often using DNA sequencing. The laboratory reports the test results in writing to a person's doctor or genetic counselor.

Routine newborn screening tests are done on a small blood sample obtained by pricking the baby's heel with a lancet.

Risks and limitations

The physical risks associated with most genetic tests are very small, particularly for those tests that require only a blood sample or buccal smear (a procedure that samples cells from the inside surface of the cheek). The procedures used for prenatal testing carry a small but non-negligible risk of losing the pregnancy (miscarriage) because they require a sample of amniotic fluid or tissue from around the fetus.

Many of the risks associated with genetic testing involve the emotional, social, or financial consequences of the test results. People may feel angry, depressed, anxious, or guilty about their results. The potential negative impact of genetic testing has led to an increasing recognition of a "right not to know". In some cases, genetic testing creates tension within a family because the results can reveal information about other family members in addition to the person who is tested. The possibility of genetic discrimination in employment or insurance is also a concern. Some individuals avoid genetic testing out of fear it will affect their ability to purchase insurance or find a job. Health insurers do not currently require applicants for coverage to undergo genetic testing, and when insurers encounter genetic information, it is subject to the same confidentiality protections as any other sensitive health information. In the United States, the use of genetic information is governed by the Genetic Information Nondiscrimination Act (GINA) (see discussion below in the section on government regulation).

Genetic testing can provide only limited information about an inherited condition. The test often can't determine if a person will show symptoms of a disorder, how severe the symptoms will be, or whether the disorder will progress over time. Another major limitation is the lack of treatment strategies for many genetic disorders once they are diagnosed.

Another limitation to genetic testing for a hereditary linked cancer, is the variants of unknown clinical significance. Because the human genome has over 22,000 genes, there are 3.5 million variants in the average person's genome. These variants of unknown clinical significance means there is a change in the DNA sequence, however the increase for cancer is unclear because it is unknown if the change affects the gene's function.

A genetics professional can explain in detail the benefits, risks, and limitations of a particular test. It is important that any person who is considering genetic testing understand and weigh these factors before making a decision.

Other risks include incidental findings—a discovery of some possible problem found while looking for something else. In 2013 the American College of Medical Genetics and Genomics (ACMG) that certain genes always be included any time a genomic sequencing was done, and that labs should report the results.

Direct-to-consumer genetic testing

Direct-to-consumer (DTC) genetic testing (also called at-home genetic testing) is a type of genetic test that is accessible directly to the consumer without having to go through a health care professional. Usually, to obtain a genetic test, health care professionals such as physicians, nurse practitioners, or genetic counselors acquire their patient's permission and then order the desired test, which may or may not be covered by health insurance. DTC genetic tests, however, allow consumers to bypass this process and purchase DNA tests themselves. DTC genetic testing can entail primarily genealogical/ancestry-related information, health and trait-related information, or both.

There is a variety of DTC tests, ranging from tests for breast cancer alleles to mutations linked to cystic fibrosis. Possible benefits of DTC testing are the accessibility of tests to consumers, promotion of proactive healthcare, and the privacy of genetic information. Possible additional risks of DTC testing are the lack of governmental regulation, the potential misinterpretation of genetic information, issues related to testing minors, privacy of data, and downstream expenses for the public health care system. In the United States, most DTC genetic test kits are not reviewed by the Food and Drug Administration (FDA), with the exception of a few tests offered by the company 23andMe. As of 2019, the tests that have received marketing authorization by the FDA include 23andMe's genetic health risk reports for select variants of BRCA1/BRCA2, pharmacogenetic reports that test for selected variants associated with metabolism of certain pharmaceutical compounds, a carrier screening test for Bloom syndrome, and genetic health risk reports for a handful of other medical conditions, such as celiac disease and late-onset Alzheimer's.

Controversy

DTC genetic testing has been controversial due to outspoken opposition within the medical community. Critics of DTC testing argue against the risks involved, the unregulated advertising and marketing claims, the potential reselling of genetic data to third parties, and the overall lack of governmental oversight.

DTC testing involves many of the same risks associated with any genetic test. One of the more obvious and dangerous of these is the possibility of misreading of test results. Without professional guidance, consumers can potentially misinterpret genetic information, causing them to be deluded about their personal health.

Some advertising for DTC genetic testing has been criticized as conveying an exaggerated and inaccurate message about the connection between genetic information and disease risk, utilizing emotions as a selling factor. An advertisement for a BRCA-predictive genetic test for breast cancer stated: “There is no stronger antidote for fear than information.” Apart from rare diseases that are directly caused by specific, single-gene mutation, diseases "have complicated, multiple genetic links that interact strongly with personal environment, lifestyle, and behavior."

Ancestry.com, a company providing DTC DNA tests for genealogy purposes, has reportedly allowed the warrantless search of their database by police investigating a murder. The warrantless search led to a search warrant to force the gathering of a DNA sample from a New Orleans filmmaker; however he turned out not to be a match for the suspected killer.

Governmental genetic testing

In Estonia

As part of its healthcare system, Estonia is offering all of its residents genome-wide genotyping. This will be translated into personalized reports for use in everyday medical practice via the national e-health portal. 

The aim is to minimise health problems by warning participants most at risk of conditions such as cardiovascular disease and diabetes. It is also hoped that participants who are given early warnings will adopt healthier lifestyles or take preventative drugs.

Government regulation

In the United States

With regard to genetic testing and information in general, legislation in the United States called the Genetic Information Nondiscrimination Act prohibits group health plans and health insurers from denying coverage to a healthy individual or charging that person higher premiums based solely on a genetic predisposition to developing a disease in the future. The legislation also bars employers from using individuals’ genetic information when making hiring, firing, job placement, or promotion decisions. The legislation, the first of its kind in the United States, was passed by the United States Senate on April 24, 2008, on a vote of 95–0, and was signed into law by President George W. Bush on May 21, 2008. It went into effect on November 21, 2009.

In June 2013 the US Supreme Court issued two rulings on human genetics. The Court struck down patents on human genes, opening up competition in the field of genetic testing. The Supreme Court also ruled that police were allowed to collect DNA from people arrested for serious offenses.

In popular culture

Some possible future ethical problems of genetic testing were considered in the science fiction film Gattaca, the novel Next, and the science fiction anime series "Gundam Seed". Also, some films which include the topic of genetic testing include The Island, Halloween: The Curse of Michael Myers, and the Resident Evil series.

Ethics

Pediatric genetic testing

The American Academy of Pediatrics (AAP) and the American College of Medical Genetics (ACMG) have provided new guidelines for the ethical issue of pediatrics genetic testing and screening of children in the United States. Their guidelines state that performing pediatric genetic testing should be in the best interest of the child. In hypothetical situations for adults getting genetically tested 84-98% expressing interest in getting genetically tested for cancer predisposition. Though only half who are at risk of would get tested. AAP and ACMG recommend holding off on genetic testing for late-onset conditions until adulthood. Unless diagnosing genetic disorders during childhood and start early intervention can reduce morbidity or mortality. They also state that with parents or guardians permission testing for asymptomatic children who are at risk of childhood onset conditions are ideal reasons for pediatrics genetic testing. Testing for pharmacogenetics and newborn screening is found to be acceptable by AAP and ACMG guidelines. Histocompatibility testing guideline states that it's permissible for children of all ages to have tissue compatibility testing for immediate family members but only after the psychosocial, emotional and physical implications has been explored. With a donor advocate or similar mechanism should be in place to protect the minors from coercion and to safeguard the interest of said minor. Both AAP and ACMG discourage the use of direct-to-consumer and home kit genetic because of the accuracy, interpretation and oversight of test content. Guidelines also state that if parents or guardians should be encouraged to inform their child of the results from the genetic test if the minor is of appropriate age. If minor is of mature appropriate age and request results, the request should be honored. Though for ethical and legal reasons health care providers should be cautions in providing minors with predictive genetic testing without the involvement of parents or guardians. Within the guidelines AAP and ACMG state that health care provider have an obligation to inform parents or guardians on the implication of test results. To encourage patients and families to share information and even offer help in explain results to extend family or refer them to genetic counseling. AAP and ACMG state any type of predictive genetic testing for all types is best offer with genetic counseling being offer by Clinical genetics, genetic counselors or health care providers.

Israel

Israel uses DNA testing to determine if people are eligible for immigration. The policy where "many Jews from the Former Soviet Union (‘FSU’) are asked to provide DNA confirmation of their Jewish heritage in the form of paternity tests in order to immigrate as Jews and become citizens under Israel's Law of Return" has generated controversy.

Costs

The cost of genetic testing can range from under $100 to more than $2,000. This depends on the complexity of the test. The cost will increase if more than one test is necessary or if multiple family members are getting tested to obtain additional results. Costs can vary by state and some states cover part of the total cost.

From the date that a sample is taken, results may take weeks to months, depending upon the complexity and extent of the tests being performed. Results for prenatal testing are usually available more quickly because time is an important consideration in making decisions about a pregnancy. Prior to the testing, the doctor or genetic counselor who is requesting a particular test can provide specific information about the cost and time frame associated with that test.