title: Clinical, enzymatic, and molecular characterisation of a Portuguese family with a chronic form of GM2-gangliosidosis B1 variant.
abstract: 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.
authors.affiliation: Instituto de Genética Médica Jacinto de Magalhães, Unidade de Enzimologia, Porto, Portugal.
authors.forename: M G
authors.initials: MG
authors.lastname: Ribeiro
authors.forename: T
authors.initials: T
authors.lastname: Sonin
authors.forename: R A
authors.initials: RA
authors.lastname: Pinto
authors.forename: A
authors.initials: A
authors.lastname: Fontes
authors.forename: H
authors.initials: H
authors.lastname: Ribeiro
authors.forename: E
authors.initials: E
authors.lastname: Pinto
authors.forename: M M
authors.initials: MM
authors.lastname: Palmeira
authors.forename: M C
authors.initials: MC
authors.lastname: Sá Miranda
mesh_terms: D000328:Adult; D000483:Alleles; D000595:Amino Acid Sequence / Q000235:genetics; D001120:Arginine / Q000235:genetics; D004252:DNA Mutational Analysis; D005678:G(M2) Ganglioside; D005733:Gangliosidoses / Q000201:enzymology / Q000235:genetics* / Q000503:physiopathology; D054818:Hexosaminidase A; D006639:Histidine / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010375:Pedigree; D010641:Phenotype; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011174:Portugal; D001619:beta-N-Acetylhexosaminidases / Q000235:genetics*
chemical_list: D005678:G(M2) Ganglioside; D006639:Histidine; D001120:Arginine; D054818:Hexosaminidase A; D001619:beta-N-Acetylhexosaminidases