| a frequent tyrosinase gene mutation associated with type i-a (tyrosinase-negative) oculocutaneous albinism in puerto rico. | we have determined the mutations in the tyrosinase gene from 12 unrelated puerto rican individuals who have type i-a (tyrosinase-negative) oculocutaneous albinism (oca). all but one individual are of hispanic descent. nine individuals were homozygous for a missense mutation (g47d) in exon i at codon 47. two individuals were heterozygous for the g47d mutation, with one having a missense mutation at codon 373 (t373k) in the homologous allele and the other having an undetermined mutation in the hom ... | 1993 | 8434585 |