NGS-based 100-gene panel of hypopigmentation identifies mutations in Chinese Hermansky-Pudlak syndrome patients

Hermansky-Pudlak syndrome (HPS) is a rare recessive disorder characterized by hypopigmentation, bleeding diathesis, and other symptoms due to multiple defects in lysosome-related organelles. Ten HPS subtypes have been identified with mutations in HPS1 to HPS10. Only four patients with HPS-1 have been reported in Chinese population. Using next-generation sequencing (NGS), we have screened 100 hypopigmentation genes and identified four HPS-1, two HPS-3, one HPS-5, and three HPS-6 in Chinese HPS patients with typical ocular or oculocutaneous albinism and the absence of platelet dense granules together with other variable phenotypes. All these patients except one homozygote were compound heterozygotes. Among these mutations, 14 were previously unreported alleles (four in HPS1, three in HPS3, two in HPS5, five in HPS6). Our results demonstrate the feasibility and utility of NGS-based panel diagnostics for HPS. Genotyping of HPS subtypes is a prerequisite for intervention of subtype-specific symptoms.