Sex-linked chorioretinal heredodegenerations.

The sex-linked chorioretinal heredodegenerations are progressive chorioretinal degeneration or choroideremia, sex-linked pigmentary retinopathy and sex-linked choroidal sclerosis. In chroroideremia the hemizygote male is fully affected, but the female heterozygote carrier shows fundus abnormalities (irregular pigmentation of the retinal periphery). The involvement of some females can be explained by Lyon's inactivation theory. The sex-linked pigmentary retinopathy is either recessive or intermediate or exceptionally dominant. In the intermediate form the female carriers show a tapetoretinal golden reflex. The sex-linked choroidal sclerosis is probably an intermediate stage in the development of a chorioretinal degeneration into choroideremia. All these degenerations must be differentiated from ocular albinism, which is also sex-linked with clinical stigmata in the female carriers (fundus changes and iris-translucency).