Research Information System
22nd World Congress of Pathology and Laboratory Medicine, Busan, South Korea, 30 August - 03 September 2003, pp.257-261
Erroneous enzymatic genotyping of Tay-Sachs disease may arise with thermal inactivation assay in families that harbour an allele coding for a heat-labile Hex B. An infantile Turkish Tay-Sachs patient who was misdiagnosed as a B1 variant by showing 28% Hex A activity to neutral substrate 4-methyluinbelliferyl-beta-D-glucosaminide (MUG) with thermal inactivation assay was searched for the point mutations in exon 13 mid 14 resulting in thermolabile Hex B. Although point mutations affecting the coding region of P-subunit gene were not found, a 2 bp polymorphism (TG) in the 3' untranslated region (3'UTR) of Hex B gene was found. Thus, this polymorphism may affect the level of beta-subunit in thermal inactivation assay, it would account or not account for thermolability of beta-subunit. Based on these results, we can suggest that the. heat lability of Hex B is the result of more than one genetic defect.