Functional evaluation of a novel GLA causative mutation in Fabry disease

Abstract

Background: Fabry disease (FD), a rare X-linked α-galactosidase A (GLA) deficiency, resulting in progressive lysosomal accumulation of globotriaosylceramide in a variety of cell types. More and more disease-causing mutations in GLA have been identified in FD due to the advancement of molecular diagnostic tools. We found a novel mutation in a Chinese family with predominant Fabry's disease nephropathy.

Methods: All coding regions and exon-intron splice junctions of the GLA gene were sequenced to find sequence variations. We evaluated the impact on the GLA protein by analysis of the GLA mRNA, by sequential analysis and homology modeling, and by site-directed mutagenesis and in vitro expression studies.

Results: We identified a novel heterozygous missense mutation c.280T>C in our patient with variable phenotypic presentations of renal involvement. The novel GLA variant results in low expression of GLA mRNAs, impaired or loss of the disulfate bridge structure of wild-type GLA, reduced GLA activity and defected nuclear shape in the GFP-GLA-MT transfected HEK293T cells.

Conclusion: A novel GLA missense mutation, c.280T>C (Cys94Arg), was found in a Chinese family with predominant renal manifestations of FD. Our study reveals the pathogenesis of c.280T>C mutation to FD and provides scientific foundation for accurate diagnosis and precise medical intervention for FD.

Keywords: Fabry disease; missense variant; novel mutation.