This disease has always been considered to affect men only. Women, who represent the carrier state, may show fundus changes but have never been considered to have functional disease. A case history of a female patient with choroideremia is presented, showing not only the typical fundus changes but also marked impairment in night vision, constriction of visual fields, limited dark adaptation, and electroretinographic extinction. It is suggested, genetically, that this is an extreme example of Lyonization or the result of modifying genes which are, at present, not clearly understood.
Harris GS, Miller JR. ChoroideremiaVisual Defects in a Heterozygote. Arch Ophthalmol. 1968;80(4):423-429. doi:10.1001/archopht.1968.00980050425003