Variable expression of retinopathy in a pedigree of patients with incontinentia pigmenti

Purpose: To characterize the varied ocular manifestations of incontinentia pigmenti (IP) in a large pedigree. Methods: All available members of the kindred who were affected with IP were examined with ophthalmoscopy, wide-field color photos, and fluorescein angiography. Results: Individual family members demonstrated variable expression of retinopathy characteristic of IP. There was severe retinopathy in two eyes: one associated with concurrent persistent fetal vasculature and another with rhegmatogenous retinal detachment. Another individual with biopsy-confirmed IP demonstrated no retinopathy in either eye. When present, retinopathy manifested asymmetrically between eyes of the same individual. Conclusion: Cutaneous manifestations of IP are irregular and nonuniform due to lyonization of the X chromosome. In this report, we identify asymmetric retinal disease between eyes in the same individual and variable retinal findings within the kindred. These differences may be explained by random inactivation of the X chromosome or other epigenetic modifications.