Selective screening for lysosomal storage disorders in a large cohort of minorities of African descent shows high prevalence rates and novel variants

Abstract

Abstract Population studies point to regional and ethnicity‐specific differences in genetic predisposition for some lysosomal storage disorders (LSDs). The aim of the study was to determine the prevalence of the three treatable forms of lysosomal storage disorders (Gaucher disease [GD], Pompe disease [PD], and Fabry disease [FD]) in a cohort of mostly urban‐dwelling individuals of African ancestry, a previously unknown genetic landscape for LSDs. Large‐scale selective multistep biochemical and genetic screening was performed in patients seeking healthcare for various health concerns. Fluorimetric enzyme assays for GD, PD, and FD were performed on dried blood spots. Targeted gene sequencing was performed on samples that showed significantly lower enzyme activities ( G; p.T158A, (b) c.503G > T; p.R168L, (c) c.1985del. Regarding FD, two subjects had pathogenic GLA mutations, and four had single nucleotide polymorphisms in the 5'UTR, previously implicated in modulating gene expression. The findings highlight a higher incidence of abnormal enzyme levels and pathogenic mutations in the target population reflecting ancestry‐based specific genotype and phenotype variations.

Keywords

• African‐Americans
• Fabry disease
• Gaucher disease
• large‐scale screening
• lysosomal storage disorders
• Pompe disease