Background Historically, CRX mutations have been associated with cone-rod dystrophy, cone dystrophy, Leber's congenital amaurosis, and retinitis pigmentosa. There is recent emerging evidence of an adult-onset macular dystrophy phenotype. We review the published literature and discuss the first case of heterozygous CRX R90 W macular dystrophy. Materials and Methods The patient received serial ophthalmic examination and imaging. Genetic testing was performed by MyRetinaTracker with the use of a retinal dystrophy panel. Results A 55-year-old Caucasian male patient without a prior medical history presented for evaluation of decreased vision in the right eye. Visual acuity was 20/32 both eyes, and his fundus examination was notable for an incomplete ring-shaped macular atrophy with foveolar sparing in both eyes. Fundus autofluorescence was notable for hypo-autofluorescence of the ring and fluorescein angiography for transmission hyperfluorescence. Full-field ERG and EOG were normal, while mfERG showed central depression. His lesion was clinically diagnosed as benign concentric annular macular dystrophy, but genetic testing revealed a heterozygous mutation in CRX (c.268 C > T, p.R90 W). A three-generation family tree did not reveal other members with known macular dystrophy. Given the lack of documentable autosomal dominant inheritance and the presence of a CRX mutation, the patient's diagnosis was revised to adult-onset macular dystrophy. Conclusions We believe this to be the first case of adult onset macular dystrophy associated with heterozygous CRX R90 W mutation.
Keywords: CRX; R90W; adult onset macular dystrophy; benign concentric annular macular dystrophy.