ELP1 and Fabry disease: The RNA sequencing (RNA-Seq) evaluation of the transcriptome of FD patient fibroblasts homozygous for the IKBKAP IVS20 + 6 T > C mutation following RECTAS treatment revealed a highly selective action of RECTAS on IKBKAP-FD exon 20, with the second-highest ΔPSI (percent spliced-in) of 618 altered splicing events with ≥0.1 of | ΔPSI | (Fig. 1b, c and Supplementary Data 1).