Screening for NDP Mutations in 44 Unrelated Patients with Familial Exudative Vitreoretinopathy or Norrie Disease

Abstract

Purpose: To screen mutations in the norrin (NDP) gene in 44 unrelated Chinese patients with familial exudative vitreoretinopathy (FEVR, 38 cases) or Norrie disease (6 cases) and to describe the associated phenotypes.

Methods: Of the 44 patients, mutation in FZD4, LRP5, and TSPAN12 was excluded in 38 patients with FEVR in previous study. Sanger sequencing was used to analyze the 2 coding exons and their adjacent regions of NDP in the 44 patients. Clinical data were presented for patients with mutation.

Results: NDP variants in 5 of the 6 patients with Norrie disease were identified, including a novel missense mutation (c.164G>A, p.Cys55Phe) in one patient, two known missense mutations (c.122G>A, p.Arg41Lys; c.220C>T, p.Arg74Cys) in two patients, and a gross deletion encompassing the two coding exons in two patients. Of the 5 patients, 3 had a family history and 2 were singleton cases. No mutation in NDP was detected in the 38 patients with FEVR.

Conclusions: NDP mutations are common cause of Norrie disease but might be rare cause for FEVR in Chinese.

KEYWORDS::

• NDP
• Norrie disease
• Familial exudative vitreoretinopathy
• Mutation
• Chinese

ACKNOWLEDGMENTS

The authors thank the family members for their participation.

Declaration of interest: This study was supported by the National Science Fund for Distinguished Young Scholars (30725044 to Q.Z.) and National 973 Plan of China (2010CB529904 to Q.Z.). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.