DIAGNOSIS AND CARRIER DETECTION OF TAY-SACHS DISEASE - DIRECT DETERMINATION OF HEXOSAMINIDASE-A USING 4-METHYLUMBELLIFERYL DERIVATIVES OF BETA-N-ACETYLGLUCOSAMINE-6-SULFATE AND BETA-N-ACETYLGALACTOSAMINE-6-SULFATE

  • 1 January 1985
    • journal article
    • research article
    • Vol. 37  (4) , 733-740
Abstract
4-Methylumbelliferyl-6-sulfo-2-acetamido-2-deoxy derivatives of .beta.-D-glucopyranoside and .beta.-D-galactopyranoside were prepared by direct sulfation of the commonly used unsulfated derivatives. Both sulfated substrates were highly specific for hexosaminidase A, and in fractionated serum, cells and tissue preparations, < 2.5% of these activities were associated with hexosaminidase B and the intermediate isozyme fractions. Serum and leukocytes from patients with infantile Tay-Sachs disease, including a patient with thermolabile hexosaminidase B, had < 2% of noncarrier activities. Carrier values were clearly separated from those of noncarriers, and no problems were encountered in utilizing sera from pregnant women. The percent hexosaminidase A values as derived from the ratio between the activities toward the sulfated and unsulfated substrates in the same specimen were comparable to those obtained by the heat-inactivation method (except for subjects with thermolabile hexosaminidase B) and may be helpful in genotype determination in borderline cases.