Exudative Vitreoretinopathy 7
A number sign (#) is used with this entry because of evidence that exudative vitreoretinopathy-7 (EVR7) is caused by heterozygous mutation in the CTNNB1 gene (116806) on chromosome 3p22.
For a general phenotypic description and a discussion of genetic heterogeneity of exudative vitreoretinopathy, see EVR1 (133780).
Clinical FeaturesPanagiotou et al. (2017) studied 2 unrelated families, 1 Japanese (family F410) and 1 Hawaiian of Japanese origin (family F258), segregating autosomal dominant nonsyndromic exudative vitreoretinopathy. In family F410, the proband presented at age 11 with very low vision, and funduscopy showed retinal avascularity, exudation, retinal holes, and bilateral retinal detachment. He had 1 brother who was similarly affected, with retinal avascularity, exudation, and bilateral tractional folds; another brother was clinically unaffected and had a normal fundus examination at age 9 years. Their father showed abnormal retinal vessels and retinal avascularity, whereas their paternal grandmother showed only unilateral focal retinal degeneration on fluorescein angiography. In family F258, the proband was assessed in her late teens and found to have a retinal detachment in her left eye with proliferative vitreoretinopathy and temporal traction, resulting in a severe retinal fold through the macula; despite vitrectomy with silicone oil, her vision was only hand movements in that eye. Her right eye had temporal macular dragging that was stabilized with laser treatment and she maintained good vision in that eye (20/40). She had an affected younger brother, diagnosed at age 10 and stabilized with laser treatments. Their father had nystagmus and severe retinal scarring and was registered blind; at last examination in his fifth decade, his vision was limited to hand movements in 1 eye and no light perception in the other.
Molecular GeneticsBy whole-exome sequencing followed by PCR and Sanger sequencing in a multiethnic cohort of 36 families in which at least 1 member had been diagnosed with EVR, and in whom mutation in known EVR-associated genes had been excluded, Panagiotou et al. (2017) identified heterozygous mutations in the CTNNB1 gene in affected individuals from 2 families of Japanese origin: a missense mutation (R710C; 116806.0024) in family F410, and a truncating mutation (116806.0025) in family F258. They also identified a 1-bp insertion in CTNNB1 (116806.0023) in a Chinese infant who was initially diagnosed with nonsyndromic EVR but who was found at age 3 years to have global developmental delay and dysmorphic facial features (see MRD19, 615075).