Ribeiro M G, Sonin T, Pinto R A, Fontes A, Ribeiro H, Pinto E, Palmeira M M, Sá Miranda M C
Instituto de Genética Médica Jacinto de Magalhães, Unidade de Enzimologia, Porto, Portugal.
J Med Genet. 1996 Apr;33(4):341-3. doi: 10.1136/jmg.33.4.341.
Mutations in the hexosaminidase A gene (HEXA) causing the B1 variant of GM2-gangliosidosis result in the presence of a mutant enzyme protein with a catalytically defective alpha subunit. A rare and panethnically distributed mutation, transition G533A (Arg178His), is known to be a common allele among Portuguese patients with the subacute phenotype. We now report the presence of an Arg178His allele in three Portuguese sibs with a chronic form of the disease, who carry the transition G755A (Arg252His) on the second allele. This novel mutation is the first B1 allele to be associated with an adult phenotype.
己糖胺酶A基因（HEXA）的突变导致GM2神经节苷脂贮积症B1型，产生一种具有催化缺陷α亚基的突变酶蛋白。一种罕见且全人种分布的突变，即G533A转换（Arg178His），已知是葡萄牙亚急性表型患者中的常见等位基因。我们现在报告在三名患有慢性疾病形式的葡萄牙同胞中存在Arg178His等位基因，他们的第二个等位基因携带G755A转换（Arg252His）。这种新突变是第一个与成人表型相关的B1等位基因。
