Novel Mutation in FRMD7 Gene in X-linked Congenital Nystagmus

ABSTRACT

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.