A splicing mutation of the tyrosinase gene causes yellow oculocutaneous albinism in a Japanese patient with a pigmented phenotype

Background: Yellow oculocutaneous albinism (OCA) that is caused by tyrosinase gene mutations shows two characteristics: extreme hypopigmentation at birth and the eventual development of yellow or blond hair. Objective: We studied a Japanese girl who had brown hair, a lighter skin color than her unaffected family and brown eyes at 9 months of age. Methods: We performed direct sequencing analyses of the tyrosinase gene in her genomic DNA. Results: The patient was a compound heterozygote for the +Delta C310 mutation (known to result in absent melanogenic activity) and a second t --> a transition at the 3' end of intron 2. Conclusion: The t --> a transition has previously been reported as a splicing mutation in other Caucasian patients with a typical yellow OCA phenotype, However, this patient showed much more pigmentation than that reported in Caucasians, Therefore, we estimate that the mild phenotype results from her genetic pigment background.