[Carrier state in X-linked ocular albinism: a proof of the validity of Lyon's hypothesis in man].

The finding of an irregular patchy fundus pigmentation in the mother of a boy with ocular albinism was interpreted as Lyon's effect on the fundus, i.e., the mosaic-like effect caused by a pathologic X-chromosome in the female carrier. It was thus possible to diagnose the more frequent X-linked form in this family.