Whole-Gene Deletions of Cause Familial Exudative Vitreoretinopathy.

Familial exudative vitreoretinopathy (FEVR) is an inherited disorder characterized by abnormalities in the retinal vasculature. The gene is associated with FEVR, but the prevalence and impact of copy number variation (CNV) on FEVR patients are unknown. The aim of this study was to better understand the genetic features and clinical manifestations of patients with CNVs. A total of 651 FEVR families were recruited. Families negative for mutations in FEVR-associated genes were selected for CNV analysis using SeqCNV. Semiquantitative multiplex polymerase chain reaction and multiplex ligation-dependent probe amplification were conducted to verify the CNVs. Four probands were found to carry whole-gene deletions of , accounting for 5% (4/80) of probands with mutations and 0.6% (4/651) of all FEVR probands. The four probands exhibited similar phenotypes of unilateral retinal folds. FEVR in probands with CNVs was not more severe than in probands with missense mutations ( = 1.000). Although this is the first report of CNVs and the associated phenotypes, the interpretation of CNVs should be emphasized when analyzing the next-generation sequencing data of FEVR patients because of their high prevalence.