Genetic Counseling

I

Introduction

Genetic Counseling, medical specialty that helps parents and prospective parents evaluate and cope with their risk of passing hereditary disorders to their children. Genetic counseling also helps individuals assess the possibility that they will get a medical condition known or suspected to have a genetic basis, such as Huntington’s disease, breast cancer, or Alzheimer’s disease.

In the United States at least 1 infant in every 100 is born with a disorder caused by an alteration in 1 or more of the estimated 20,000 to 25,000 human genes. Genes are segments of deoxyribonucleic acid (DNA), the hereditary molecule found in the chromosomes of cells. The severity of genetic disorders varies from mild conditions such as color blindness to serious diseases such as Duchenne muscular dystrophy and Tay-Sachs disease.

In most cases, genetic counseling is provided by a team of health experts at a medical center. The team typically consists of counselors who have graduate training in genetics, psychology, population statistics, and medical education, along with physicians who have advanced training in human genetics. The team also may include nurses, social workers, and psychologists who have specialized skills in patient education and public health.

Genetic counseling may involve more than one visit between a counselor and a client, who may be an individual, a couple, or an entire family. During the first visit, the counselor gathers information about the client’s family medical history. The counselor may discuss options for diagnostic tests that could help determine if a person is at risk for passing an inherited disorder on to children or is susceptible to a particular genetic disease. After considering these options, the client may choose to undergo testing at that time or in a follow-up session. When testing is completed, the genetic counselor analyzes the family history and test results to determine whether a genetic disorder exists within a family and, if so, how it is inherited. The counselor then discusses those conclusions with the client. Genetic counselors help the client cope with the emotional repercussions of the diagnosis as well as any practical concerns. Genetic counselors respect the privacy of the individual and family, keeping all information exchanged during counseling sessions confidential.

---

---

II

Who Benefits from Genetic Counseling

Many prospective parents use genetic counseling to help resolve issues surrounding pregnancy and infertility. Genetic counseling is helpful to parents who already have a child with a genetic disorder so they can learn more about the condition and the chance that their other children may be affected. People with a family history of life-threatening diseases may consult a genetic counselor to learn the probability that they will develop a disease. Others seek genetic counseling to determine the likelihood that they will develop a disease that occurs more frequently in their ethnic group.

A

Prospective Parents

A couple that is thinking about conceiving a child may want to consider genetic counseling for several reasons. For instance, many women aged 35 or older seek genetic counseling because they are at a higher risk than younger women of giving birth to a child with a chromosomal abnormality. These abnormalities occur when a child inherits all or part of an extra copy of a chromosome. Down syndrome, the most common chromosomal disorder, is almost nine times more common in babies born to women aged 40 than those born to women aged 30. Couples who already have a child who was born with a genetic disorder may seek genetic counseling to determine the risk that future children may be similarly affected.

Expecting couples concerned about the health of their unborn baby may request genetic counseling to learn if the baby is at risk for a disease. A pregnant woman may worry that she has been exposed to factors that can hurt the development of her fetus, such as infectious diseases, medications, alcohol, nonmedical drugs, or radiation. Genetic counseling can prove useful when adopting a child. Parents interested in adopting a child whose biological parent or grandparent has an inherited condition may seek counseling to determine if this family history is likely to affect the child.

The parents of a newborn diagnosed with a genetic disease may ask a genetic counselor to explain the progression of the disease and describe the types of treatments required to keep their baby healthy. Infertile couples or those who have experienced two or more miscarriages may pursue genetic counseling to learn whether a genetic condition may be responsible for their reproductive difficulties.

B

People with a Family History of Disease

Genetic counseling can also help people who have a family history of common diseases, such as cancer, heart disease, or mental illness. Although these diseases are not routinely considered genetic disorders, they often have a hereditary component when they affect multiple members of a family. A genetic counselor may recommend that family members set up regular physical examinations or screening tests with a medical specialist. These regular examinations can detect health problems early, when the conditions may be easier to treat. Counseling may also help family members make informed decisions about diet, exercise, and surgery options that can help reduce the chance that the condition will develop, or that can lessen the condition’s severity.

	More from Encarta
	•  Important Notice: MSN Encarta to be discontinued. Learn more. •  Presidential Myths Quiz •  Coffee break: Recharge your brain