Genetic Counseling Health Article

Definition

Genetic counseling is a communication process by which personal genetic risk information is translated into practical information for families. Genetic counselors are health care professionals with specialized training and experience in the areas of medical genetics and counseling. Genetic counselors are able to assist individuals and families by:

• Helping people to understand information about birth defects or genetic disorders. This includes explaining patterns of inheritance, recurrence risks, natural history of diseases, and genetic testing options.
• Providing nondirective supportive counseling regarding emotional issues related to a diagnosis or testing options.
• Helping individuals and families make decisions with which they are comfortable, based on their personal ethical and religious standards.
• Connecting individuals and families with appropriate resources, such as support groups or specific types of medical clinics, locally and nationally.

Purpose

There are several purposes or aspects to be addressed within the scope of genetic counseling. These include obtaining a pedigree; tracing ethnicity; exploring issues of consanguinity; and documenting exposures to toxins, diseases, or environmental agents during pregnancy.

Pedigree

In all types of genetic counseling, an important aspect of the counseling process is information gathering about family and medical history. Information gathering is performed by drawing a chart called a pedigree. A pedigree is made of symbols and lines that represent a family history. To accurately assess the risk of inherited diseases, information about three generations of the family, including health status and cause of death, is usually needed. If a family history is complicated, information from more distant relatives may be helpful, and medical records may be requested for any family members who have had a genetic disorder. Thorough examination of a family history may enable a counselor to calculate the probability of occurrence of genetic disorders in the future.

Ethnicity

In obtaining a family history, a genetic counselor asks about a person's ethnicity or ancestral origin. There are some ethnic groups that have a higher chance of being carriers of some genetic diseases or abnormalities. For instance, the chance that an African American is a carrier of a gene for sickle cell disease is one in 10. People of Jewish or central European ancestry are likely to be carriers of several conditions, including Tay-Sachs disease, Canavan's disease and cystic fibrosis. People of Mediterranean ancestry are likely to be carriers of a type of anemia called thalassemia. Genetic counselors discuss inheritance patterns of these diseases, carrier risks, and genetic screening or testing options.

Consanguinity

Another question a genetic counselor asks in obtaining a family history is whether the couple are related to one another by blood. The practice of marrying or having children with relatives is infrequent in the United States, but is more common in some countries. When two people are related by blood, there is an increased chance for their children to be affected with conditions that are inherited in a recessive pattern. In recessive inheritance, each parent of a child affected with a disease carries a single gene for a disease. The child gets two copies, one from each parent, and is affected. People who have a common ancestor are more likely than unrelated people to be carriers of genes for the same recessively inherited disorders. Depending on family history and ethnic background, blood tests can be offered to couples to get more information about the chance of these conditions occurring.

Exposures during pregnancy

During prenatal genetic counseling, the counselor will ask about pregnancy history. If a woman has taken medications or has had exposure to a potentially harmful substance from the environment such as a chemical, toxin, or radiation, the genetic counselor can discuss the possibility of adverse effects. Ultrasound is often a useful tool to look for some effects of exposure.

Precautions

There are no physical precautions that are needed before genetic counseling. However, persons who will receive the results of genetic tests should be prepared mentally and emotionally for the possibility of unpleasant information. This includes discussing if they want to know the results of genetic testing and what choices they may have to make based on the information supplied.

Types of genetic counseling

Genetic counselors work with people concerned about the risk of an inherited disease or condition. These people represent several different populations. Prenatal genetic counseling is provided to couples that have an increased risk of birth defects or inherited conditions, and are expecting a child or planning a pregnancy. Pediatric genetic counseling is provided to families with children suspected of having a genetic disorder or with children previously diagnosed with a genetic disorder. Adult genetic counseling is provided to adults with clinical features of an inherited disease or a family history of an inherited disease. Cancer genetic counseling is provided to those with a strong family history of certain types of cancer. Ethics are an important component of genetic counseling.