Updated Analysis of Albinism in Japan: 290 Families With Novel Pathological Variants

We present an updated analysis of albinism in Japan, encompassing both oculocutaneous albinism (OCA) and ocular albinism (OA), based on 290 families, which expands our previous study by 100 additional families. The overall frequency distribution of major subtypes remained consistent with our previous findings: OCA4 remains the most prevalent subtype (67 patients, 23.1%), followed by OCA1 (57 patients, 19.7%), Hermansky-Pudlak syndrome (HPS) 1 (35 patients, 12.1%), and OCA2 (30 patients, 10.3%). Notably, our expanded analysis identified patients with rare subtypes, including OCA3, OCA6, HPS2, HPS3, HPS5, and HPS6, as well as OA, further demonstrating the genetic diversity of albinism in the Japanese population. Through comprehensive genetic screening of the additional 100 families, we identified 17 patients harboring previously unreported pathological variants across multiple albinism subtypes. These findings expand the variant spectrum of albinism in Japan, provide valuable insights for genetic counseling, and underscore the critical importance of comprehensive clinical evaluation and long-term multidisciplinary follow-up for patients with albinism, particularly those with HPS subtypes.