As intronic GLA variants such as IVS4+919G>A have been reported to cause late-onset FD with cardiac phenotype by altering GLA mRNA processing [7,23], we analyzed the potential effect of the intronic variants (IVS2-81_-77delCAGCC; IVS4-16A>G and IVS6-22C>T) co-segregating with the -10T allele by exon trapping experiments in an endothelial cell line (Figure 6). Here, GLA is linked to Fabry disease.