Patients underwent genetic analysis of selected albinism (Tyrosine and P gene) and HPS genes (HPS-1 and HPS-3) by screening for common mutations and exon sequencing with DNA screening.
This retrospective review identified 170 individuals with a specific type of albinism identified by mutation(s) in a gene known to cause albinism (for OCA1, OCA2, and Hermansky-Pudlak syndrome ([HPS]) or a specific phenotype (white hair and no melanin pigment in OCA1A; pigmentary mosaicism in the obligate carriers for males with OA1).
Mutations in RAB27A, LYST, and AP3B1 give rise to FHL associated with oculocutaneous albinism, and patients with FHL are usually only screened for mutations in these genes when albinism is observed.
Our findings expand the molecular, cellular, and clinical spectrum of HPS-2 and call for an increased index of suspicion for this diagnosis among patients with features of albinism, bleeding, and neutropenia.