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Recently, an acute restriction of imiglucerase has occurred as a result of viral contamination and manufacturing problems. A position statement from the European Working Group for Gaucher Disease and European Gaucher Alliance established a set of key recommendations for identifying and monitoring at-risk patients. In Spain, a profile of the shortage situation was obtained through follow-up of patients with Gaucher disease (GD) and compliance with the therapy recommendations. Here we describe a group of patients, with modified doses of imiglucerase, during the shortage. Fifty adult GD1 patients (25 males/25 females), previously on ERT, were analysed before and after the 6-month shortage. The mean age was 45.3 ± 15.3 years (range: 18-84). The mean Severity Score Index at diagnosis was 8.7 ± 3.8 (range: 3-19); 20% of patients were splenectomized; and 78% had bone disease. During the shortage, 23 patients (46%) discontinued therapy; as complications in this group only one patient suffered a bone crisis and another anaemia (Hb

Background : Gaucher disease (GD) is a heterogeneous disease characterized by an impaired activity of the lysosomal glucocerebrosidase. This heterogeneity is attributed in part to the existence of a large number of mutations in the corresponding gene. Subjects and methods : To establish genotype–phenotype relationships, we analyzed the residual enzyme activities of six naturally occurring mutations found in Spanish population in the glucocerebrosidase gene [c.160G > A (V15M), c.485T>C (M123T), c.914C>T (P266L), c.1124T>C (L336P), c.1207A>C (S364R) and c.1510–1512delTCT (S465del)]. The mutated genes were subcloned into the mammalian expression vector pCR® 3.1 and expressed by transient transfection in COS cells. The enzymatic activity of the expressed protein were measured and compared with the wild-type human glucocerebrosidase cDNA. Also, two previously alleles, c.1226A>G (N370S) and c.1448T>C (L444P), were used for comparative purposes. Results : The residual activity of the expressed proteins using the synthetic substrate (4-methylumbelliferyl-β- d -glucopyranoside, 4MU-Glu) ranged from 5.5% (for the 3-bp deletion) to 42.7% (for S364R mutation) of the activity of the wild-type enzyme. Conclusion : The present analyses may help to better understand the molecular basis and the pathogenesis of Gaucher disease. However, results of expression of mutated enzymes are necessary but not sufficient to explain the ultimate clinical outcome of Gaucher disease.

ABSTRACT Background. Gaucher disease is an autosomal recessive disorder resulting from mutations in the glucocerebrosidase gene (GBA). The lack of full genotype/phenotype correlation complicates counseling regarding clinical outcome and treatment recommendations. Subjects and methods. Several mutations in the human β-glucosidase gene associated with Gaucher disease in 16 Spanish families were identified utilizing a combination of methods: enzymatic restriction, PCR–SSCP, and sequence analyses. Expression studies were performed following the introduction of the mutagenized human acid β-glucosidase cDNA into COS-1 cells, and the residual enzyme activities of the mutant protein were measured and compared with the normal cDNA. Results. The identified mutations and corresponding residual enzyme activities of the expressed 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-1 cells are useful methods to increase our understanding of causality in Gaucher disease and the correlation between disease severity, gene defects, and residual enzyme activity. Our study demonstrates the functional consequences of the identified human β-glucosidase mutations (T134P, S364N, G377S, P391L, and G325W) and provide evidence for the molecular and biochemical basis of Gaucher disease, among patients of Spanish ancestry.