AUTOSOMAL-DOMINANT CONGENITAL CATARACT - INTEROCULAR PHENOTYPIC VARIABILITY

Purpose: While intrafamilial morphologic heterogeneity of autosomal do minant congenital cataracts has been well established, interocular var iation in individual patients of described pedigrees is small. The aut hors describe a seven-generation family with 48 of 138 individuals kno wn to be affected with autosomal dominant congenital cataracts of the pulverulent type. Affected patients exhibit a seemingly random express ion of either unilateral or bilateral lens opacities. Methods: Ophthal mic and medical histories were obtained, complete ophthalmologic exami nations were performed, blood samples were drawn, and transformed lymp hoblastoid lines were established on 53 patients. Eighty-five members of the family were unable to be examined. Results: Twenty-eight of the 53 individuals examined had congenital cataracts. Of these patients, 19 eyes (8 right eyes and 11 left eyes) were unilateral and 9 were bil ateral. The clinically unaffected eye in patients with unilateral cata racts showed no evidence of lenticular opacity under detailed slit-lam p examination. Severity of the cataracts included a subtle unilateral zonular cataract with 20/20 visual acuity, bilateral inner fetal nucle ar pulverulent opacities with 20/16 visual acuity in both eyes, and de nse unilateral and bilateral nuclear cataracts requiring early surgica l removal. Incorporating the historic data on patients who were not ex amined, we found 48 affected members (28 unilateral, 17 bilateral, 3 o bligate carriers who were not examined). Conclusions: Hereditary catar acts typically are symmetric in affected individuals. The authors desc ribe a large pedigree with the apparently random expression of an auto somal dominant gene as either unilateral or bilateral cataract. To the ir knowledge, this is the first such family described in the literatur e. Currently, work is under way to determine if the causative gene is linked to previously defined cataract loci on chromosomes 1, 2, or 16.