Medicine: Genetics for the Community

Few legacies are more lethal than Tay-Sachs disease, a rare ailment that occurs almost exclusively among Jews of Eastern European ancestry. Caused by an inherited enzyme deficiency, the disease begins to affect infants at about six months of age, causes brain deterioration, and usually kills the patient before his fifth birthday. Science has yet to discover either a cure or a treatment. But doctors at Baltimore's John F. Kennedy Institute believe that they can prevent it. In a unique experiment to bring genetics to the community, they are seeking to identify those who carry the deadly Tay-Sachs gene so that the birth of doomed infants can be avoided.

The Baltimore program owes its origin to several recent scientific discoveries in the field of molecular biology. One was the identification of the enzyme hexosaminidase-A, the lack of which causes Tay-Sachs disease. Another was the development of a technique for taking cells from the amniotic fluid, the clear, amber liquid in which the developing fetus floats, and analyzing the cells for the presence-or absence-of the essential enzyme. The most important step, however, was perfecting a simple blood test to identify adults who carry the defective gene but are themselves unaffected by it.

Pulpit Participation. The screening campaign is being conducted by Dr. Michael Kaback, an assistant professor of pediatrics at the Johns Hopkins University School of Medicine, and Dr. Robert Zeiger of the National Cancer Institute. Says Kaback: "A successful genetic counseling program requires three things. First, the population at risk must be easily identifiable. Second, there must be a simple, inexpensive method of detecting carriers of the disease. Third, there must be a means of diagnosing the disease in utero." Many diseases meet two of the three criteria. Tay-Sachs is the only disease that meets all three.

There are more than 240,000 Jews in the Baltimore-Washington area, and the doctors decided to focus on those most likely to bear children: 80,000 people between the ages of 18 and 43. To reach and test this high-risk population, Kaback and Zeiger sought the support of local rabbis and leaders of Jewish organizations. Few refused to provide it. Rabbis took to their pulpits to inform their congregations about the disease and to urge them to participate in the experiment. Jewish women's organizations not only distributed thousands of leaflets but provided volunteers to conduct the actual screenings. "This," said Kaback, "was a program by the community for the community."