Clinical and molecular phenotyping of a child with Hermansky-Pudlak syndrome-7, an uncommon genetic type of HPS.

•The first pediatric patient was identified with Hermansky-Pudlak syndrome type 7 (HPS-7).•Exome sequencing revealed a homozygous nonsense mutation in the DTNBP1 gene, previously reported in a Portuguese adult.•Human HPS-7 cells showed negligible Dysbindin protein expression and DTNBP1 mRNA level similar to that of a normal control.•This HPS-7 patient's reduced Dysbindin protein expression resulted from a mechanism other than nonsense mediated decay.