Prenatal Diagnosis
A Key Program For GeneCare Medical Genetics Center

While the center offers complete genetic services for physicians and patients, it is perhaps best known for its work in prenatal diagnosis - the process of evaluating the developing fetus when there may be an increased risk for a specific abnormality. That special interest flows from Dr. Buchanan's background: After training at NC State, the University of Michigan, Harvard, and the University of Oregon, he came to UNC-Chapel Hill to set up the prenatal genetics diagnosis program, which he headed for a dozen years before opening the GeneCare Center in 1983. Now the center has a second location at George Washington University, in Washington, DC, and is part of an international research network.

PRENATAL TESTING

Parents dream about and pray for the delivery of a healthy child, but many of them, anxious for a variety of reasons (see box), spend time with Dr. Buchanan, his principal clinical associate, Dr. Caroline H. Laundon, or one of the experienced and skillful genetic counselors on staff. Both Drs. Buchanan and Laundon are medical geneticists and clinical cytogenetics certified by the American Board of Medical Genetics.

"Testing to allay fears of abnormalities in the fetus most often involves amniocentesis, which is the removal of a small amount of amniotic fluid surrounding the fetus during development", Dr. Buchanan notes. "This procedure takes five to ten minutes, with very little discomfort. Discarded cells from fetal skin are present in the amniotic fluid and can be grown in the laboratory for chromosome and/or chemical tests."

"Chromosome analysis serves to reassure most parents their fetus does not have a chromosome abnormality. It can also show the chromosomal sex of the fetus."

Amniocentesis and ultrasound are very safe procedures. The ultrasound exam, a painless 30-minute procedure, is performed before amniocentesis, to confirm the dating of the pregnancy, to detect certain birth defects, and to determine if there are twins. At GeneCare, we offer continuous ultrasound-guided amniocentesis for all procedures- the safest possible way to do these tests."

Many women and couples are wise to consider prenatal diagnosis, says Dr. Buchanan, under a number of conditions including:

1. The woman who is pregnant or planning to become pregnant and will be 34 or older at delivery; the father who will be 42 or older at delivery; the mother who has epilepsy, lupus erthematosus or severe diabetes.

2. Couples who have had an affected with a chromosomal abnormality, such as Down syndrome; a chromosome rearrangement, or other birth defects.

3. Couples who are known or possible carriers of an inherited disorder, such as hemophilia, muscular dystrophy, or cystic fibrosis.

The GeneCare Center offers first trimester tests, principally to screen for chromosome abnormalities such as Down syndrome, and second trimester tests to screen women who may have a higher risk of having a baby with such birth defects as open spine as well as some chromosome abnormalities.

WHO NEEDS GENETIC TESTING?

Genetic testing is appropriate, Dr. Buchanan believes, for:

1. Persons concerned about the diagnosis and inheritance of birth defects, mental retardation, developmental delay, or other disorders in the family.

2. Persons concerned about exposure to drugs, x-rays, infectious agents, or other factors which might affect a pregnancy.

3. Couples who have experienced a combination of two or more spontaneous abortions, stillbirths, or neonatal deaths.

4. Couples who may be related.

5. Males with unexplained infertility.

6. Persons of Jewish or Black heritage who are concerned about having a baby with Tay-Sachs or sickle cell anemia, respectively.