Based on occurrence of mutation, OCA is identified as nonsyndromic OCA genes (TYR, OCA2, TYRP1, and SLC45A2) and syndromic OCA genes (HPS1, AP3B1, HPS3, HPS4, HPS5, HPS6, DTNBP1, BLOC1S3, PLDN, LYST, MYO5A, RAB27A, and MLPH) [4, 5]. Here, HPS4 is linked to oculocutaneous albinism.