TYR and oculocutaneous albinism: Furthermore, a screening of 120 cases of human oculocutaneous albinism (OCA) revealed the absence of any mutation in the coding sequence of the tyrosinase gene for 35 cases [15], 24 of these 35 were found in probands with the OCA1B condition, where minimal-to-moderate amounts of cutaneous and ocular pigment could be found.