Later retinal degeneration following childhood surgical aphakia in a family with recessive CRYAB mutation (p.R56W)

Abstract

Purpose: To describe later retinal degeneration following childhood cataract surgery without intraocular lens implantation in a consanguineous family with developmental cataract from homozygous p.R56W mutation in CRYAB, a gene that encodes a heat-shock protein (αB-crystallin) in both retina and the lens.Methods: Prospective ophthalmologic examination and venous blood sampling for diagnostic CRYAB sequencing in the 12 available family members (7 siblings and their 2 parents, the siblings’ maternal aunt and her son, and the siblings’ maternal grandmother).Results: Those who underwent childhood cataract surgery (2 siblings, their mother, their maternal aunt) or who had visually-insignificant lens opacities (2 siblings, their maternal grandmother) were homozygous for p.R56W CRYAB mutation. Among these 7 affected family members, clinically-obvious rod-cone degeneration was present only in the only 2 adults who were aphakic since childhood from cataract surgery.Conclusions: Recessive p.R56W CRYAB mutation shows variable expressivity for lens opacity. Decades of aphakia increases retinal light exposure and may be an environmental risk factor for significant retinal degeneration in patients homozygous for the mutation.