Mass screening program in a high risk population group in Israel designed for the prevention of Tay Sachs disease (TSD) has been in operation since 1973. A fully automated fluorometric procedure has been developed to determine the total and heat stable hexosaminidase in serum. In 34 obligatory heterozygotes the mean value of serum hexosaminidase A activity (HAA) was found to be 43.2% ± S.D. 5.24%. On the basis of these values 95% tolerance limits were calculated and the upper limit of HAA in serum of 56.3% was determined. All screened individuals with a value below 56.3% HAA in serum were considered as possible heterozygotes and were recalled for an examination of leucocyte HAA, and only on this basis was heterozygosity established. A total of 3009 individuals (1590 males and 1419 females) without known relatives with TSD were screened. The total number of heterozygotes identified was 112 (3.72%), and in 15 (0.5%) individuals the results were inconclusive, giving a carrier rate of 1:27.1-1:23.7. In 4 couples both mates were defined as heterozygotes and their 5 pregnancies monitored. In 3 of the 5 pregnancies the antenatal diagnosis revealed normal infants. In the other 2 the fetus was shown to be affected with TSD, the pregnancies were terminated and diagnosis of TSD verified. At present, in the absence of feasible therapy for the management of TSD (and other inborn lysosomal disorders) the mass screening for the detection of carriers in high risk population followed by prenatal diagnosis and selective abortions offers a way to control this fatal disease.
|State||Published - 1976|