Genetic counseling is the process by which patients or relatives, at risk of an inherited disorder, are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options open to them in management and family planning. This complex process can be separated into diagnostic (the actual estimation of risk) and supportive aspects.
Genetic counselors 
The National Society of Genetic Counselors (NSGC) officially defines genetic counseling as the understanding and adaptation to the medical, psychological and familial implications of genetic contributions to disease. This 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 and adaptation to the risk or condition.
A genetic counselor is an expert with a Master of Science degree in genetic counseling. In the United States they are certified by the American Board of Genetic Counseling. In Canada, genetic counselors are certified by the Canadian Association of Genetic Counsellors. Most enter the field from a variety of disciplines, including biology, genetics, nursing, psychology, public health and social work. Genetic counselors should be expert educators, skilled in translating the complex language of genomic medicine into terms that are easy to understand.
Genetic counselors work as members of a health care team and act as a patient advocate as well as a genetic resource to physicians. Genetic counselors provide information and support to families who have members with birth defects or genetic disorders, and to families who may be at risk for a variety of inherited conditions. They identify families at risk, investigate the problems present in the family, interpret information about the disorder, analyze inheritance patterns and risks of recurrence, and review available genetic testing options with the family.
Genetic counselors are present at high risk or specialty prenatal clinics that offer prenatal diagnosis, pediatric care centers, and adult genetic centers. Genetic counseling can occur before conception (i.e. when one or two of the parents are carriers of a certain trait) through to adulthood (for adult onset genetic conditions, such as Huntington's disease or hereditary cancer syndromes).
Any person may seek out genetic counseling for a condition they may have inherited from their biological parents.
A woman, if pregnant, may be referred for genetic counseling if a risk is discovered through prenatal testing (screening or diagnosis). Some clients are notified of having a higher individual risk for chromosomal abnormalities or birth defects. Testing enables women and couples to make a decision as to whether or not to continue with their pregnancy, and helps provide information that can be used to prepare for the birth of a child with medical issues.
A person may also undergo genetic counseling after the birth of a child with a genetic condition. In these instances, the genetic counselor explains the condition to the patient along with recurrence risks in future children. In all cases of a positive family history for a condition, the genetic counselor can evaluate risks, recurrence and explain the condition itself.
Counseling session 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 counselees wish to go ahead with testing, an appointment is organized and the genetic counselor acts as the person to communicate the results.
Reasons and results 
Families or individuals may choose to attend counseling or undergo prenatal testing for a number of reasons.
- Family history of a genetic condition or chromosome abnormality
- Molecular test for single gene disorder
- Increased maternal age (35 years and older)
- Increased paternal age (40 years and older)
- Abnormal maternal serum screening results or ultrasound findings
- Increased nuchal translucency measurements on ultrasound
- Strong family history of cancer
- Predictive testing for adult-onset conditions
Detectable conditions 
Many disorders cannot occur unless both the mother and father pass on their genes, such as Cystic Fibrosis. Some diseases can be inherited from one parent, such as Huntington disease, and DiGeorge syndrome. Other genetic disorders are the cause of an error or mutation occurring during the cell division process (e.g.trisomy). Testing can reveal conditions that are easily treatable as long as they are detected (Phenylketonuria or PKU). Results from genetic testing may also reveal:
Genetic counselors as support 
Genetic Alliance states that 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. The field of genetic counseling is rapidly expanding and many counselors are taking on "non-traditional roles" which includes working for genetic companies and laboratories. 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.
Prenatal genetic counseling 
If an initial noninvasive screening test reveals a risk to the baby, clients are encouraged to attend genetic counseling to learn about their options. Further prenatal investigation is beneficial and provides helpful details regarding the status of the fetus, contributing to the decision-making process. Decisions made by clients are affected by factors including timing, accuracy of information provided by tests, and risk and benefits of the tests. Counselors present a summary of all the options available. Clients may accept the risk and have no future testing, proceed to diagnostic testing, or take further screening tests to refine the risk. Invasive diagnostic tests possess a small risk of miscarriage (1-2%) but provide more definitive results. Increased risk result is commonly presented in positively and negatively ways. While families seek direction and suggestions from the counselors, they are reassured that no right or wrong answer exists. When discussing possible choices, counselor discourse predominates and is characterized by examples of what some people might do. Discussion enables people to place the information and circumstances into the context of their own lives. Clients are given a decision-making framework they can use to situate themselves. Counselors focus on the importance of individual choice based on the experiences, morals, and viewpoints of the couple/individual/family. Testing is offered to provide a definitive answer regarding the presence of a certain genetic condition or chromosomal abnormality. There is often no therapy or treatment available for these conditions, and as such parents may have to make decisions regarding the management of the pregnancy.
After attending counseling, women have the option of accepting the risk revealed and having no further treatment during their pregnancy. They may choose to undergo noninvasive screening (e.g. triple screen, cell-free fetal DNA screening) or invasive diagnostic testing (amniocentesis or chorionic villus sampling).
Attitudes toward counseling 
The plethora of information available can be overwhelming and counselors spend a large proportion of time clarifying details. Prenatal screening was first introduced nearly four decades ago, yet gaps still exist in public knowledge about the screening program. The general public is familiar with Down syndrome (trisomy 21), but is not aware of more uncommon conditions such as trisomy 18 (historically known as Edwards syndrome) and trisomy 13 (Patau syndrome). Clients are usually aware of diagnostic testing from friends, TV/press, or because of family history.
No simple correlation has been found between the change in technology to the changes in values and beliefs towards genetic testing.
See also 
- "Definitions of Genetic Testing". Definitions of Genetic Testing (Jorge Sequeiros and Bárbara Guimarães). EuroGentest Network of Excellence Project. 2008-09-11. Retrieved 2008-08-10.[dead link]
- Genetic Alliance Site [Internet]. [cited 2010 Oct 29]. Available from: http://www.geneticalliance.org/.
- Hodgson JM et al. 2010. “Testing Times, Challenging Choices”: An Australian Study of Prenatal Genetic Counseling. J Genet Counsel 19:22-37.
- Macdonald F. 2008. Practice of prenatal diagnosis in the UK. Clin Risk 14(6):218-221.
- Dolan SM. 2009. Prenatal Genetic Testing. Pediatr Ann 38(8):426:430.
- Stefansdottir V et al. 2010. Effects of knowledge, education, and experience on acceptance of first trimester screening for chromosomal anomalies. Acta Obstet Gynecol Scand 89(7):931-8.
- Singer E et al. 2008. Trends in U.S. Attitudes toward Genetic Testing, 1990-2004. Public Opinion Quarterly 72(3):446-458.
- National Society of Genetic Counselors
- American Board of Genetic Counseling
- Canadian Association of Genetic Counsellors
- Association of Genetic Nurses and Counsellors (UK)