ClinVar

Description

This male patient was born to related parents from Brazil who both have brown hair and brown skin. He was referred to us for a suspicion of Hermansky-Pudlak syndrome. He was born with white hair and white skin and at age 10 he had blond hair, creamy skin and blue eyes with no pigmentation tendency. He had some pigmented and achromic naevi, and no history of skin cancer. He presented with congenital nystagmus, pupillary red reflection, photophobia, myopia, astigmatism and low visual acuity. Upon ophthalmological examination, retinal hypopigmentation was observed. Visual evoked potentials, electroretinography and optic coherence tomography could not be performed. His medical history is positive for bleeding diathesis but no signs of lung or digestive tract disease or immune defect were reported. NGS found a homozygous 4 bp frameshift deletion in the coding sequence of BLOC1S3, NM_212550.3: c.338_341del (p.(Leu113Argfs*15). This deletion is reported once, at heterozygous state, in the GnomAD database. ACMG Classification is in favor of a pathogenic variant (PVS1, PM2, PP1).