Beesley CE, Jackson M, Young EP, Vellodi A, Winchester BG. Molecular defects in Sanfilippo syndrome type B (mucopolysaccharidosis IIIB).
J Inherit Metab Dis 2005;
28:759-67. [PMID:
16151907 DOI:
10.1007/s10545-005-0093-y]
[Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Accepted: 04/13/2005] [Indexed: 10/25/2022]
Abstract
Sanfilippo syndrome type B (mucopolysaccharidosis IIIB) is an autosomal recessive disease that is caused by the deficiency of the lysosomal enzyme alpha-N-acetylglucosaminidase (NAGLU). NAGLU is involved in the degradation of the glycosaminoglycan (GAG) heparan sulphate, and a deficiency results in the accumulation of partially degraded GAGs inside lysosomes. Early clinical symptoms include hyperactivity, aggressiveness and delayed development, followed by progressive mental deterioration, although there are a small number of late-onset attenuated cases. The gene for NAGLU has been fully characterized and we report the molecular analysis of 18 Sanfilippo B families. In total, 34 of the 36 mutant alleles were characterized in this study and 20 different mutations were identified including 8 novel changes (R38W, V77G, 407-410del4, 703delT, A246P, Y335C, 1487delT, E639X). The four novel missense mutations were transiently expressed in Chinese hamster ovary cells and all were shown to decrease the NAGLU activity markedly, although A246P did produce 12.7% residual enzyme activity.
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