ABSTRACT
Objective To analyze the clinical features and NDP gene variants in patients with Norrie disease and familial exudative vitreoretinopathy,(FEVR).Methods Sixteen patients who were diagnosed as FEVR and 3 patients who were diagnosed as Norrie disease underwent detailed ocular examinations in Beijing Tongren Hospital from 2012 to 2018.Peripheral venous blood was drawn from patients and their family members for extration of genomic DNA.All exons of NDP gene were analyzed by direct sequencing of PCR-amplified DNA fragments.This study was approved by Joint Committee on Clinical Investigation of Beijing Tongren Hospital,and patients information and venous blood collection were done after the informed consents were obtained.Results Four unreported NDP gene mutations were detected in one FEVR patient and 3 Norrie disease patients:c.217T＞C (p.S73P),c.2T＞C (p.M1),c.194G＞T (p.C65F) and c.384C＞G (p.C128W).One patient who was clinically diagnosed as FEVR had no symptom but the avascular zone on the bilateral peripheral retina.The three Norrie disease patients who were clinically diagnosed as Norrie disease all appearred to have bilateral congenital blindness,mass in the vitreous and retinal detachment,and one in the three Norrie disease patient had evident mental retardation.Conclusions The results of this paper extend NDP gene mutation spectrum,and NDP gene is further confirmed to be the casuse of Norrie disease.