Autosomal Recessive Inheritance of Familial Exudative Vitreoretinopathy

Abstract

Abstract: : Purpose: To confirm the existence of autosomal recessive Familial Exudative Vitreoretinopathy and document the phenotype by clinical examination of four consanguinous pedigrees with the disease. Methods: One large consanguinous recessive pedigree with FEVR was ascertained originating from Pakistan.Two additional smaller pedigrees were examined with the same ethnic origin whereas a third originated from Saudi Arabia. Ophthalmic examination of the proband, siblings and both parents of all pedigrees was performed using slit lamp biomicroscopy and indirect ophthalmoscopy. Clinical findings together with a detailed family history were used to determine the mode of inheritance. Results: Examination of the largest consanguinous recessive pedigree with FEVR originating from Pakistan revealed three affected siblings born to first cousin parents. Each sibling had an unusually severe form of the disease with retinal traction, retinal folds and consequently markedly reduced visual acuity. Both parents were deemed clinically normal. Examination of the three additional smaller pedigrees revealed a similar picture, with the proband in each documented as a severely affected individual with features typical of FEVR. In each pedigree the parents were first cousins with a normal fundus examination. Conclusions: This study provides further evidence for the existence of autosomal recessive FEVR. A cluster of families has been examined originating from Pakistan suggesting that consanguinous recessive FEVR in this population may be a severe phenotype with early onset. This finding may provide a powerful tool for linkage analysis in order to map new loci for FEVR.

Keywords: retinal degenerations: hereditary • genetics