Exome sequencing identified a compound heterozygous genotype in the HPS1 gene (NM_000195.3) in the proband: 1) pathogenic frameshift variant c.1189delC; p.(Gln397Serfs*2), resulting in a premature stop codon, associated with HPS; and 2) previously undescribed nonsense variant, c.1507C > T; p.(Gln503*), resulting in a premature stop codon, implying a loss of 197 amino acids or more likely, nonsense-mediated decay of the mRNA degradation (Fig. 4). This evidence concerns the gene HPS1 and Hermansky-Pudlak syndrome.