Identification of a rare missense mutation in GJB1 and prenatal diagnosis in a Chinese family with CMT: A case report.

RATIONALE: Charcot-Marie-Tooth disease (CMT) is a highly heterogeneous genetic disorder. To date, more than 90 genes have been implicated in the pathogenesis of CMT. Here, we report the identification of a rare causative mutation in a Chinese family with CMT and a pregnant patient underwent prenatal diagnosis.

PATIENT CONCERNS: A 33-year-old woman with 21 + 6 weeks of pregnancy presented with progressive weakness of distal extremities after 23 years of age. A total of 8 individuals in 4 generations of her family had similar muscle weakness. On proband whole-exome sequencing (WES), a rare c.121G > A variant in the GJB1 gene was identified.

DIAGNOSIS: Based on the clinical and genetic findings, this patient was finally diagnosed with CMT.

INTERVENTIONS: The prenatal diagnosis was performed on the proband fetus.

OUTCOMES: The fetus did not carry this rare variant, and the pregnancy continued.

LESSONS: Our findings provide the first clinical evidence for the causative role of GJB1 c.121G > A variant in CMT. WES is a valuable method for diagnosing patients with CMT.