Genetic Counseling

What is genetic counseling and do I really need it before I try to get pregnant? Today, more and more parents-to-be are asking themselves this question.

Genetic counseling is nothing more than consulting a specially trained genetic counselor or health care professional to identify whether any high risk traits exist that may be passed on to your child. Although an obvious consideration for couples and families who have demonstrated genetic abnormalities or concerns, there is also the very real risk of an inherited defective gene being transmitted unknowingly by a parent who is unaware of the disease that might be present.

A gene is a piece of DNA that is assigned a certain trait, such as blue eyes versus brown, that is passed on from generation to generation, making up one portion of our chromosomes, the entities that formulate each physical characteristic we possess. Every cell in our bodies contains pairs of these chromosomes that determine our makeup. When a sperm fertilizes an egg, half of every chromosomal pair comes from the mother and the other half from the father.

An abnormality in one or more of these chromosomes can result in a genetic disorder. A defect in a single gene can also be the culprit, often referred to as X-linked, dominant or recessive genetic disorders. In X-linked disorders, the defective gene is located on the X chromosome (also known as the female chromosome).

In dominant disorders, the defective gene is the dominant one, overriding the healthy gene from the other parent; recessive disorders are when both genes in the pair are abnormal. Defects exist not only because of abnormalities such as spontaneous mutation or cell division errors but also because of exposure to environmental agents, chemicals and other toxins (including lead, industrial chemicals, pesticides, radiation and drugs).

First off, genetic counseling should not be considered a necessity for most couples that plan on getting pregnant. However, if certain risk factors are already apparent, it should be undertaken, ideally but not limited to prior to attempting toget pregnant. These risk factors include one or more of the following:

• Mothers-to-be over 35 years of age
• Prior birth of a child or existence of a close relative with a genetic disorder or birth defect
• Presence of an inherited disease in one or more close relatives
• Prenatal testing that has revealed abnormal results
• Results of an amniocentesis which identified a chromosomal defect

Certain ethnic groups also possess a propensity toward particular inherited defects and disorders. If you or your partner is a member of one of these groups, you may also want to consider genetic counseling. These groups include:

• Africans, African Americans and some Mediterranean ancestries (sickle cell anemia)
• Italian, Greek or Middle Eastern ancestries (thalassemia)
• Central or Eastern European (Ashkenazi) Jews and French-Canadian ancestry (Tay-Sachs disease)

If you decide to participate in genetic counseling, it’s helpful to be prepared. Begin by creating a comprehensive history of the blood relatives on both sides of each family that have suffered particular diseases or disorders and why they may have occurred (genetic or otherwise). Be prepared to answer questions on topics such as:

• Any family history of cancer, hypertension, heart problems, diabetes and/or multiple births (twins, etc.)
• Any other diseases or disorders that appear to run in the family, including but not limited to genetic diseases such as hemophilia, muscular dystrophy, cystic fibrosis, and multiple sclerosis
• Family members with any form of mental retardation or birth defect
• Family members who have experienced problems with pregnancies, such as miscarriages, stillbirths and infertility
• Health of parents and immediate family members, alive and dead
• Ethnic background/ancestry
• Grounds for any fears you might have that your baby might be born with a genetic disorder or birth defect

A trained genetic counselor can help identify potential problems or disorders, discuss with you the risks involved and the information you need to have before making the decision to get pregnant, analyze the likelihood of transmission of a particular type of disorder and explain all the available options open to you.