Abstract
Purpose: :
To identify Fzd4 gene mutations in familial exudative vitreoretinopathy (FEVR) and retinopathy of prematurity (ROP) patients.
Methods: :
The CDS of the Fzd4 gene was amplified from genomic DNA of clinically diagnosed FEVR (n=35) and ROP (n=48) patients. The sequences of the PCR products were directly obtained by Dye Terminator Cycle Sequencing.
Results: :
Fzd4 mutations were identified in three of the 35 FEVR patients (9%). One patient had a novel heterozygous mutation in exon 2 (C117R). The other two FEVR patients had the same double heterozygous mutation (P33S; P168S). Interestingly, these 2 patients were referred with a diagnosis of ROP and underwent laser ablation at an outside hospital. However, a careful review of their birth history made FEVR more likely. Three of the 48 ROP patients (6%) had the same double heterozygous mutation found in the two FEVR patients. No other Fzd4 mutations were found in the ROP patients.
Conclusions: :
The proportion of adFEVR attributed to mutations in the Fzd4 gene, has been previously reported to be between (4% to 20%). ROP has a similar phenotype to FEVR, however the patients have no family history and are premature. It is interesting that the same double heterozygous mutation was found in both FEVR and ROP patients (5/62 =8%). This mutation has been reported previously in an adFEVR patient. It is estimated that as many as 90% of adFEVR patients are asymptomatic. The high percentage of clinically diagnosed patients with the double heterozygous mutation identified in this study, may indicate that patients with this mutation have a higher propensity to develop more severe disease.
Keywords: gene screening • retinopathy of prematurity • retina