title: Serum beta-hexosaminidases in pregnancy.
abstract: Serum contains several hexosaminidase forms. Two, HEX A and HEX B, migrate in both DEAE cellulose and isoelectric focussing systems like their tissue counterparts. A major group of serum hexosaminidases migrate in an intermediate position. These forms, collectively named HEX 1, increase during pregnancy and obscure carrier detection for Tay-Sachs and Sandhoff's disease. Using DEAE-cellulose chromatography, HEX A, I, and B, can be clearly separated. In normals, activity ratios of A/B are 4.03 +/- 1.33. During pregnancy the ratio falls slightly to 3.01 +/- 1.08. In Tay-Sachs heterozygotes the ratio is only 1.08 +/- 0.35 and falls during early pregnancy to 0.53 +/- 0.23. In Sandhoff heterozygotes the DEAE chromatograms appear normal with higher than normal A/B ratios but in sera, from both pregnant and nonpregnant carriers, the HEX B and HEX I forms are 50% heat labile. During pregnancy, serum can be used as a reliable source of HEX for heterozygote identification for both Sandhoff's and Tay-Sachs disease.
mesh_terms: D002848:Chromatography, DEAE-Cellulose; D005260:Female; D006580:Genetic Carrier Screening; D006596:Hexosaminidases / Q000097:blood*; D006801:Humans; D007525:Isoelectric Focusing; D011247:Pregnancy; D012497:Sandhoff Disease / Q000201:enzymology; D013661:Tay-Sachs Disease / Q000201:enzymology
chemical_list: D006596:Hexosaminidases