CMT 환자들에서 Neurofilament Light Chain (NEFL) 유전자 돌연변이 분석

Abstract

Background: Charcot-Marie-Tooth (CMT) disease is the most common form of inherited motor and sensory neuropathy. Neurofilament light chain polypeptide (NEFL) is one of the most abundant cytoskeletal components of the neuron. The NEFL gene encoding the neurofilament light chain plays an important role in the axonal structure that includes an extensive fibrous network in the cytoplasm of the neuron. Mutations in the NEFL gene are also present in CMT2E, CMT type 1 and Dejerine-Sottas syndrome. However, there have been no reports to investigate the NEFL genes in Korean CMT patients. Therefore, we investigated to find the clinical characteristics in patients with the NEFL gene mutation. Methods: We examined mutations of the NEFL gene in 125 Korean CMT families. Mutations were confirmed by the sequencing of both strands. Nerve conduction studies were carried out on CMT patients having each mutation. Results: Three pathogenic mutations were found in 3 families, and 2 polymorphisms in 2 families. Two mutations (Leu334Pro, Pro22Arg) were determined too novel, and those were not detected in 105 healthy controls. A de novo missense mutation was found in a CMT family with the NEFL mutation. The frequency of the NEFL mutation was 2.4%, which was similar in Europeans, and lower than those found in Japanese. Pro22Arg and Glu397Lys mutations showed demyelinating neuropathy and Leu334pro mutation showed axonal neuropathy. Conclusions: We found NEFL mutations in patients with sporadic or dominantly inherited CMT. NEFL mutations should be considered in the evaluation of CMT or related neuropathies with various clinical features.