Mutational Analysis of the Neurofilament Light Chain (NEFL) Gene in Patients with Charcot-Marie-Tooth Disease

J Korean Neurol Assoc > Volume 23(5); 2005 > Article

Journal of the Korean Neurological Association 2005;23(5): 642-649.

CMT 환자들에서 Neurofilament Light Chain (NEFL) 유전자 돌연변이 분석

조현지, 정기화a 선우일남b 박기덕 김대성c 서범천b 이미선a 윤은경a 최병옥

이화여자대학교 의과대학 신경과학교실, 공주대학교 생명과학과a, 연세대학교 의과대학 신경과학교실b, 부산대학교 의과대학 신경과학교실c

Mutational Analysis of the Neurofilament Light Chain (NEFL) Gene in Patients with Charcot-Marie-Tooth Disease

Hyun Ji Cho

Department of Neurology, College of Medicine, Ewha Womans University, Seoul; Department of Biological Science, Kongju National Universitya, Gongju; Department of Neurology, College of Medicine, Yonsei Universityb, Seoul; Department of Neurology, College of Medicine, Pusan National Universityc, Busan, Korea

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. KeyWords:Charcot-Marie-Tooth disease, Neurofilament protein L, Gene, Mutation