New compound heterozygous CYP4V2 mutations in bietti crystalline corneoretinal dystrophy

Bietti crystalline corneoretinal dystrophy (BCD) is an autosomal recessive retinal dystrophy which is caused by the mutations of CYP4V2, usually progressing to legal blindness by the 5th or 6th decade of life. Here we identified CYP4V2 compound heterozygous mutations in two female siblings with BCD without subjective symptoms. After 381 pathogenic genes related to retinal diseases were screened by targeted sequence capture array techniques and confirmed by Sanger sequencing, two compound heterozygous mutations in CYP4V2 were found. One was missense mutation c.1198C>T (p.R400C) and the other was frameshift mutation c.802-8_810delinsGC (p.V268_E329del). Optical coherence tomography (OCT) showed that the ellipsoid zone was absent in the macular regions and electroretinogram (ERG) revealed poor cone and rod responses. Compound heterozygous mutations in CYP4V2 are related to the BCD. Our study expands our knowledge of heterogenic phenotypes and genotypes through genetic diagnosis of the BCD patients.