TYR and ocular albinism: OCA is an autosomal recessive disorder, to date mutations of six genes have been associated with non-syndromic forms of OCA.3 OCA type 1 is the most common type of albinism in European populations, caused by mutations in the tyrosinase gene (TYR).3 4 Ocular albinism (OA) is an X linked disorder caused by GPR143 mutations and characterised by predominantly ocular defects.5