Yan Xu1, Liang Li2, Hai-Tao Ren1, Bin Yin2, Jian-Gang Yuan2, Xiao-Zhong Peng3, Bo-Qin Qiang2, Li-Ying Cui4. 1. Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College (CAMS & PUMC), Beijing, China. 2. State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, CAMS & PUMC, Beijing, China; Neuroscience Center, CAMS, Beijing, China. 3. State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, CAMS & PUMC, Beijing, China; Neuroscience Center, CAMS, Beijing, China. Electronic address: pengxiaozhong@pumc.edu.cn. 4. Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College (CAMS & PUMC), Beijing, China; Neuroscience Center, CAMS, Beijing, China. Electronic address: pumchcuily@sina.com.
Abstract
AIMS: To investigate the association of the Nectin/Necl family genes with the risk of developing NMOSD. METHODS: Whole-exome sequencing was performed on two familial NMOSD cases and two unaffected family members. Additionally, 106 patients with sporadic NMOSD and 212 healthy controls (HCs) underwent screening for mutant Necl2. Finally, the molecular weight and cellular localization of mutant NECL2 was examined in transfected HeLa cells. RESULTS: We identified a novel deletion mutation in Necl2 (c.1052_1060delCCACCACCA; p. Thr351_Thr353del), which was associated with disease manifestation in the NMOSD familial cases. The frequency at which the mutation occurred in patients with sporadic NMOSD was significantly higher than for HCs (5.7% and 0, respectively; p<0.01). The mutation was located in the extracellular domain close to the transmembrane region, at a point in the protein sequence characterized by threonine enrichment. The mutant NECL2 had a lower molecular weight and exhibited defective trafficking to the cell surface. CONCLUSIONS: Our results suggest that the Necl2 mutation identified herein may be associated with the risk of developing NMOSD. Furthermore, mutated NECL2 may play a role in the pathogenesis of the disease, potentially through its roles in axonal regeneration and/or via neuron-glia interactions that are relevant to myelination.
AIMS: To investigate the association of the Nectin/Necl family genes with the risk of developing NMOSD. METHODS: Whole-exome sequencing was performed on two familial NMOSD cases and two unaffected family members. Additionally, 106 patients with sporadic NMOSD and 212 healthy controls (HCs) underwent screening for mutant Necl2. Finally, the molecular weight and cellular localization of mutant NECL2 was examined in transfected HeLa cells. RESULTS: We identified a novel deletion mutation in Necl2 (c.1052_1060delCCACCACCA; p. Thr351_Thr353del), which was associated with disease manifestation in the NMOSD familial cases. The frequency at which the mutation occurred in patients with sporadic NMOSD was significantly higher than for HCs (5.7% and 0, respectively; p<0.01). The mutation was located in the extracellular domain close to the transmembrane region, at a point in the protein sequence characterized by threonine enrichment. The mutant NECL2 had a lower molecular weight and exhibited defective trafficking to the cell surface. CONCLUSIONS: Our results suggest that the Necl2 mutation identified herein may be associated with the risk of developing NMOSD. Furthermore, mutated NECL2 may play a role in the pathogenesis of the disease, potentially through its roles in axonal regeneration and/or via neuron-glia interactions that are relevant to myelination.