Disease-causing mutations in alpha galactosidase induce aberrant splicing in vivo

Precursor messenger RNA (pre-mRNA) splicing is a critical post-transcriptional process in eukaryotic cells. The large, dynamic ribonucleoprotein (RNP) complex known as the spliceosome must assemble onto the nascent pre-mRNA and precisely excise introns and ligate exons for every splicing event. This process is largely regulated by cis-elements within the RNA transcript, such as splicing enhancers and silencers, and trans-elements such as RNA binding proteins (RBPs). Approximately 10% of all disease-causing mutations affect consensus splice site sequences, resulting in aberrant splicing, but the effects of mutations located within other splicing regulatory elements (SREs) remains poorly understood. Recent studies suggest that roughly 26% of disease-causing and nonsense mutations interfere with splicing regulatory cis-elements (Sterne-Weiler et al. 2011). In the present study, we focus on characterizing the molecular impact of mutations within exons 5 and 6 of the α-galactosidase gene (GLA) which encodes the lysosomal hydrolase alpha-galactosidase (Masson et al. 2004). Mutations in GLA can lead to a deficiency in the enzyme, resulting in Fabry Disease, a debilitating lysosomal storage disorder. Taken together, the data reveal these mutations disrupt functional elements involved in splicing regulation