Abstract
Purpose: :
To identify causal mutations in a family with retinitis pigmentosa (RP) complicated with congenital cataract, cornea thinning and high myopia.
Methods: :
A four-generation family from Luzhou, Sichuan Province of China with RP was studied by clinical and genetic analysis. Twenty two subjects from a four-generation Chinese family with RP. All family members underwent complete ophthalmologic examinations and genetic analysis. The ophthalmologic examinations included slit-lamp biomicroscopy, fundus examination, fundus fluorescein angiography, optical coherence tomography (OCT), B-scan ultrasonagraphy, central cornea thickness (CCT) and electroretinography. Genetic analysis included mutational analysis of candidate genes for RP and exome sequencing.
Results: :
Patients of the family presented with bone spicule-shaped pigment deposits in retina, retinal vascular attenuation, retinal and choroidal atrophy, as well as punctate opacity of the lens, reduced cornea thickness and high myopia. Several candidate genes were excluded as the disease-causing genes in this pedigree. Exome sequencing identified compound heterozygous IVS6-8del17bp/insGC and IVS8-2A>G mutations of the CYP4V2 gene in the patients. They were confirmed to be carried by patients only in this pedigree.
Conclusions: :
Compound heterozygous IVS6-8del17bp/insGC and IVS8-2A>G mutations of the CYP4V2 gene, known as genetic defects for Bietti crystalline corneoretinal dystrophy, were identified as causative mutations for RP of this family.