A NOVEL MISSENSE MUTATION (C522Y) IS PRESENT IN THE BETA-HEXOSAMINIDASE BETA-SUBUNIT GENE OF A JAPANESE PATIENT WITH INFANTILE SANDHOFF DISEASE

A novel missense mutation ((1565)G-->A) was identified in the cDNA and genomic DNA coding for the beta-hexosaminidase beta-subunit of a Japa nese patient with infantile Sandhoff disease. The patient was homozygo us for this mutation, which should result in a cysteine-to-tyrosine su bstitution at codon 522. Computer-assisted analysis of this amino acid substitution predicted alteration in the secondary structure in the r egion of a highly conserved sequence. An immunofluorescence study reve aled the accumulation of GM2 ganglioside in cultured fibroblasts from the patient with this mutation. (C) 1995 Academic Press, Inc.