HPS1 and Hermansky-Pudlak syndrome: Strikingly, one of the newly identified A5C events participates in an unusual AS-NMD circuitry controlling the abundance of mRNA encoding Hps1, a subunit of the Rab32/38 guanine nucleotide exchange factor (GEF) essential for biogenesis of lysosome-related organelles and mutated in patients with Hermansky-Pudlak Syndrome (HPS; OMIM: 203300; [31]–[34]).