Mutations analysis of FRMD7 gene in idiopathic congenital nystagmus families / 中华实验眼科杂志

Objective To reveal the pathogenic mutations in Chinese families with idiopathic congenital nystagmus(ICN) Methods Six families with ICN were recruited from Subei People's Hospital. DNA was extracted from peripheral blood samples of all participants. All coding and exon-intronic boundary regions of the targeted gene FRMD7 were amplified with PCR and sequenced using Sanger sequencing to detect potential pathogenic mutations. This study followed the Helsinki Declaration and was approved by the Ethics Committee of Subei People's Hospital (NO. 2015KY-126). All patients or their guardians signed informed consent. Results Three mutations (c. 902A>G, c. 1944T>A and 1945G>T) were screened in two families after co-segregation validation of intrafamilial genotype-phenotype,c. 1944T>A and 1945G>T were newly detected mutations which were not detected in 100 normal controls. No significant mutations were found in the FRMD7 coding region and adjacent splicing sites in the probands of the other four families. Conclusions Two novel pathogenic mutations of FRMD7 are discovered,which expands the pathogenic mutational spectrum of FRMD7 gene causing ICN.

Mutations analysis of FRMD7 gene in idiopathic congenital nystagmus families / 中华实验眼科杂志

Objective@#To reveal the pathogenic mutations in Chinese families with idiopathic congenital nystagmus(ICN)@*Methods@#Six families with ICN were recruited from Subei People's Hospital.DNA was extracted from peripheral blood samples of all participants.All coding and exon-intronic boundary regions of the targeted gene FRMD7 were amplified with PCR and sequenced using Sanger sequencing to detect potential pathogenic mutations.This study followed the Helsinki Declaration and was approved by the Ethics Committee of Subei People's Hospital (NO.2015KY-126). All patients or their guardians signed informed consent.@*Results@#Three mutations (c.902A>G, c.1944T>A and 1945G>T) were screened in two families after co-segregation validation of intrafamilial genotype-phenotype, c.1944T>A and 1945G>T were newly detected mutations which were not detected in 100 normal controls.No significant mutations were found in the FRMD7 coding region and adjacent splicing sites in the probands of the other four families.@*Conclusions@#Two novel pathogenic mutations of FRMD7 are discovered, which expands the pathogenic mutational spectrum of FRMD7 gene causing ICN.

Clinical characteristics of X-linked infantile nystagmus in a Chinese family / 上海交通大学学报（医学版）

Objective • To identify the clinical features of a Chinese Han family with X-linked infantile nystagmus. Methods • A Chinese family with X-linked infantile nystagmus was recruited from Department of Ophthalmology in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Peripheral blood from the members of the family was collected and molecular genetic analysis was done. The 5 patients in the family received comprehensive ocular examinations including measurement of visual acuity, degree of anomalous head posture, stereoscopic vision, binocular function, electroretinogram, visual evoked potential, optical coherence tomography, eye movement recording and cycloplegic refraction. Results • A frame-shift mutation (c.823-829delACCCTAC, p.Thr275fs) in the 9th exon of FERM domain containing protein 7 (FRMD7) in the family was found. The similar clinical features of the family included moderate impairment of visual acuity, mild astigmatism, reduced stereoscopic vision, no fusion function, and bidirectional jerk wave form. Their electroretinograms were normal, but there was a peak latency and decreased amplitudes in visual evoked potential. And the structures of maculae had no obvious abnormality. The performance of the anomalous head posture was varied. Conclusion • Thr275fs in FRMD7 protein is identified as the main factor in the Chinese family with X-linked infantile nystagmus. The clinical features of the family show a certain degree of consistency.

Current advance in molecular genetics of congenital idiopathic nystagmus / 中华实验眼科杂志

Congenital idiopathic nystagmus (CIN) is characterized by monoocular or biocular involuntary,rhythmical,repeated oscillations.CIN is often referred to congenital 'motor' nystagmus since nystagmus occurs in the absence of a clinically demonstrable defect in the visual sensory system.CIN is genetically heterogeneous,and patterns of its inheritance have been well-known to include autosomal dominant.autosomal recessive and X-linked patterns.In recent years, many different genetic loci for CIN have been mapped,and researchers have found some candidate causing-disease genes.This review focuses on the recent advances of gene mapping and candidate gene analysis for molecular research of CIN.

Novel Mutation in FRMD7 Gene in X-linked Congenital Nystagmus

BACKGROUND AND OBJECTIVES: Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. To report a novel mutation in FERM domain containing 7 (FRMD7) gene in a Korean family with CN. MATERIALS AND METHODS:Genomic DNA was prepared from peripheral blood leukocytes and direct sequencing of the entire coding and adjacent intronic regions was performed to detect sequence variation of FRMD7 gene, where mutations were found recently in patients with familial CN. The family showed an X-linked pattern of inheritance without father-to-son transmission. RESULTS: Three family members with CN exhibited two sequence variations which were a novel mutation (c. 875T>C; Leu292Pro) and a polymorphism (c. 1403G>A; Arg468His, dbSNP rs#6637934). The proband was hemizygous for both variations and his mother and maternal grandmother were heterozygous carriers. CONCLUSION: This study provides an additional evidence for mutations in FRMD7 as a common cause of X-linked CN and expands its mutation spectrum.