Identification and characterization of a novel mutation c.1090G > T (G325W) and nine common mutant alleles leading to Gaucher disease in Spanish patients

Background. Gaucher disease is an autosomal recessive disorder resulting fr om mutations in the glucocerebrosidase gene (GBA). The lack of full genotyp e/phenotype correlation complicates counseling regarding clinical outcome a nd treatment recommendations. Subjects and methods. Several mutations in th e human beta -glucosidase gene associated with Gaucher disease in 16 Spanis h families were identified utilizing a combination of methods: enzymatic re striction, PCR-SSCP, and sequence analyses. Expression studies were perform ed following the introduction of the mutagenized human acid beta -glucosida se cDNA into COS-1 cells, and the residual enzyme activities of the mutant protein were measured and compared with the normal cDNA. Results. The ident ified mutations and corresponding residual enzyme activities of the express ed protein are as follows: c.517A >C (T134P), 1%; c.721G >A (G202R), 17%; c .1090G >T (G325W), 13.9%; c.1093G >A (E326K), 26%; c.1208G >A (S364N), 4.1% ; c.1226A >G (N370S), 17,8%; c.1246G >A (G377S), 17.6%; c.1289C >T (P391L), 8.5%; c.1448T >C (L444P), 3%; and c.1504C >T (R463C), 24.5%. (Conclusions. Site-directed mutagenesis and expression in COS-I cells are useful methods to increase our understanding of causality in Gaucher disease and the corr elation between disease severity, gene defects, and residual enzyme activit y. Our study demonstrates the functional consequences of the identified hum an X -glucosidase mutations (T134P, S364N, G377S, P391L, and G325W) and pro vide evidence for the molecular and biochemical basis of Gaucher disease, a mong patients of Spanish ancestry. (C) 2001 Academic Press.