Hermansky-Pudlak oculocutaneous albinism: Clinical and genetic observations of six patients

Six patients diagnosed as Hermansky-Pudlak oculocutaneous albinos in three unrelated Puerto Rican families were studied for modes of genetic transmission and certain laboratory characteristics. The typical findings of this syndrome include a history of easy bruisability and bleeding tendency, a prolonged bleeding time, abnormal platelet aggregation, and oculocutaneous albinism with a tyrosinase-positive phenotype. This variety of albinism usually exhibits an autosomal recessive inheritance pattern, although one of the authors' families appears to manifest an autosomal dominant pattern probably due to pseudodominance. Various explanations of these genetic observations are discussed, including gene frequency, modes of inheritance, and gene linkage along with the geographical backgrounds and clinical and laboratory features of the authors' families.