Bietti crystalline dystrophy (BCD) is a rare genetic eye disease whose inheritance pattern is autosomal recessive. It is characterized by presence of crystalline lipid deposits on the retina in the second decade of life, followed by atrophy of the pigmented epithelial layer and choriocapillaris, pigment clumping, and sclerosis of the choroidal vessels. Blindness ultimately ensues. CYP4V2 was identified as a causative gene for BCD in 2004, and to date all BCD patients genetically screened were found to have mutations in this gene. To the best of our knowledge, BCD in the Iranian population has not previously been reported. Here, we report clinical and genetic data on an Iranian pedigree (BCD-100) with six BCD individuals distributed in two generations.

Diagnosis was made based on fundufscopy. Genetic analysis was performed by Sanger sequencing of the coding exons of CYP4V2.

The pedigree is highly inbred, and all affected individuals are offspring of consanguineous parents. This is consistent with autosomal recessive inheritance. Considerable phenotypic heterogeneity was noted among the affected individuals. Crystalline deposits were limited to the retina and absent in the cornea. Choroidal neovascularization was not observed. A macular hole recently became evident in one of the patients. The variation c.G1219T in CYP4V2 that causes p.Glu407*was observed in the homozygous state in exon 9 of the gene in the proband.

The clinical features in the Iranian pedigree were similar to those previously reported. The presence of macular hole has only rarely been reported. As the nonsense mutation p.Glu407* causes deletion of 119 amino acids from the carboxyl terminus of the encoded protein, it is expected to be the genetic cause of BCD in the family. The variation is novel. Segregation analysis is being performed to confirm that it is indeed cause of disease.