Differentiation of heterozygotes in recessive albinism.

Skin pigmentation was measured by reflectance spectrophotometry in 43 albinos, 44 of their relatives, and 123 random controls among Swazi subjects in southern Africa. Mean reflectance of the subject groups diminishes in the sequence affected subjects, obligate heterozygotes, other unaffected family members, random subjects, and the differences among the unaffected groups are highly significant. A discriminant function fitted to the obligate heterozygotes and random subjects is significant statistically but is not efficient enough to be applied in the diagnosis of the non-carrier state.