Thursday, November 22, 2007

Genetic Counseling

What is Genetic Counseling?
Because the nature of genetic testing is so complex, with implications for both the person being tested and his or her family, counseling is desirable before taking any genetic test and essential if results come back positive or uncertain. Unlike most medical appointments, a counseling session may be a family affair, with participation of all concerned relatives. Counselors say sometimes a dozen or more relatives attend.
A genetic counselor is a health care professional who is an expert in counseling, genetics and genetic testing. She (most today are women) reviews your family history to determine if there appears to be a hereditary pattern of disease and who might be affected. A genetic counseling session usually lasts at least an hour and includes:
gathering background information on your family and the disease under discussion
providing information on inheritance, the genetic testing procedure, the possible results and what they mean
Testing usually is not performed at the first counseling session, and there is never any pressure to take a test. Genetic counseling will educate you so you can make an informed decision. If you are feeling ambivalent, counseling won't push you in one direction or the other, but it can help you decide whether testing is right for you.
Because family history is so crucial to deciding whether testing has a chance of identifying a disease-linked mutation, a counselor may request medical records to confirm a diagnosis, especially if you're trying to determine whether a family pattern of cancer is hereditary.
Family member recollections can be inaccurate-who had which disease or even what type of disease. Many conditions either were not discussed or not diagnosed in past decades. A genetic counselor will listen to a family account and help tease out details to better identify potential patterns.
Many women never think about genetic testing until they are considering having a child or have become pregnant. Prenatal testing offers an opportunity to test for chromosomal and common genetic disorders, as well as genetic conditions that have surfaced on either side of the family or for which either parent is a carrier. Counselors recommend a preconception session to discuss carrier testing and prenatal testing options.
Privacy Concerns
Genetic counselors are committed to protecting your privacy. They will not contact other family members without your permission, though they may encourage you to share results that might affect your relatives. Many counseling centers will store records of test results separate from your main medical record to help keep the information out of the hands of insurers and employers, unless you give permission to share. (Of course, if you use insurance to pay for testing, the company will have access to your file.) If you are concerned about your privacy, ask your genetic counselor about the center's policy. Thus far, experts say, there has been little evidence of insurer or employer discrimination based on genetic testing, but that may change once such testing becomes commonplace.
Genetic Testing And Children
Up to age 18, genetic tests are used only for diagnosing conditions for which the proper care during childhood or adolescence can make a difference, not for doing carrier screening or testing for diseases that may affect children later in life (presymptomatic testing).
Newborn screening programs are now idely available for genetic diseases treatable early in life. Such a test can indicate elevated risk of a disorder, and a positive result should be followed up with further diagnostics. Below are the most commonly administered newborn screening tests, though remember that not every state administers every test (check with a health care professional to find out):
Phenylketonuria (PKU) is characterized by an inability to metabolize an amino acid called phenylalanine and causes mental retardation unless a specialized phenylalanine-free diet is put in place. Aspartame (Equal) should be avoided if you have PKU.
Hypothyroidism can interfere with growth and mental development if not treated.
Galactosemia can cause mental retardation if not treated with a diet free of a sugar called galactose, which is found in dairy products.
Sickle cell disease makes a baby more susceptible to infection but early treatment with penicillin reduces the risk.
Newborn screening programs designed to test for 30 conditions are now being introduced in some hospitals. If this type of program is not available at your hospital, you can obtain your own kit by mail and have your baby tested at the hospital or your pediatrician's office.

No comments: