Aihua Wei1, Dongjie Zang2, Xiumin Yang1and Wei Li2
Posters-Accepted Abstracts: J Clin Exp Dermatol Res
Oculocutaneous albinism (OCA) is a heterogeneous and autosomal recessive disorder with hypopigmentation in eye, hair and skin color. Six genes, TYR, OCA2, TYRP1 SLC45A2, OCA5 and SLC24A5, have been identified as causative genes for non-syndromic OCA1-6 respectively. For syndromic OCA, at least 13 genes, HPS1-9 for Hermansky-Pudlak syndrome, CHS1 for Chediak-Higashi syndrome, GS1-3 for Griscelli syndrome, have been characterized. An optimized strategy for the genotyping of more than 300 Chinese OCA patients was implemented. Over 70 previously unreported alleles in several OCA genes including TYR, OCA2, SLC45A2, SLC24A5 and HPS1 were identified. It was found that the mutational spectrum is population specific in Chinese (different from Caucasian and Japanese). The abnormal melanosomal localization of several commonly occurred alleles of TYR and SLC45A2 in Chinese OCA patients was characterized. The melanosomes in the skin melanocytes of these OCA patients was examined and found that more immatured melanosomes were present in an OCA6 patient. Furthermore, the SLC24A5 protein was reduced in steady-state levels in mouse HPS mutants with deficiencies in BLOC-1 and BLOC-2. The melanosomal localization in multiple HPS melanocytes was further investigated. Our results suggest that is required for melanosome maturation and is transported into mature melanosomes by HPS protein associated complexes (HPACs). The results of this study will be translational and significant for gene diagnosis and prenatal diagnosis of OCA in China.