Surgical outcomes of a congenital nystagmus family with a missense mutation in the FRMD7 gene

Abstract

Background: This study aimed to assess the effectiveness of surgery in the management of vertical compensatory head posture in patients with congenital nystagmus (CN) inherited in an X-linked manner in a Chinese family and determine the molecular pathogenesis of this disease. Methods: We studied 18 members belonging to four generations in a family with congenital nystagmus. Parks shift of neutral zone surgeries were performed on 7 patients with vertical compensatory head posture from the family. In addition, head posture, visual acuity, and stereopsis of the 7 patients were evaluated before and 2-years after the displacement surgeries. Gene alternations of the disease were researched by sequencing a candidate gene (FRMD7). From each generation of the family, one patient (including the proband) and one normal control were sampled for Sanger sequencing. Results: Over a median follow-up period of 2 years, the anomalous head posture, visual acuity, and stereopsis significantly improved postoperatively (P T (p.D196Y) in exon 7 of FRMD7 was co-segregated with the disease in this family. Conclusions: Parks shift of neutral zone surgeries relieved the vertical compensatory head posture and improved visual acuity and stereopsis in the primary position of CN patients. In this study, it was concluded that a missense mutation in exon 7 (c.586G > 7, p.D196Y) in FRMD7 was possibly responsible for the disease in this family.

Keywords

• X-linked congenital nystagmus
• Vertical compensatory head posture
• FRMD7 gene
• Shift of neutral zone surgery
• Surgical outcome