Background： X-linked Charcot-Marie-Tooth type 1 （CMT1 X） disease is one of the most common forms of inherited neuropathy caused by mutations in the gap junction beta-1 protein （GJB1） gene （also known as connexin...Background： X-linked Charcot-Marie-Tooth type 1 （CMT1 X） disease is one of the most common forms of inherited neuropathy caused by mutations in the gap junction beta-1 protein （GJB1） gene （also known as connexin 32）. This study presented the clinical and genetic features of a series of Chinese patients with GJB1 gene mutations. Methods： A total of 22 patients from unrelated families, who were referred to Department of Neurology, Peking University First Hospital from January 2005 to January 2016, were identified with GJBI mutations. Their clinical records and laboratory findings were retrospectively collected and reviewed. Mutations in the GJB1 gene were analyzed by targeted next-generation sequencing （NGS）. Nucleotide alternations were confirnled with Sanger sequencing. Results： The CMT1X patients predominantly showed distal muscle weakness of lower limbs with mild sensory disturbance. The mean age of onset was 15.6 ± 8.7 years （ranging from 1 year to 42 years）. The sudden onset of cerebral symptoms appeared in four patients （ 18.2%）： two were initial symptoms. One case had constant central nervous system （CNS） signs. There were 19 different heterozygous mutations, including 15 known mutations and tbur novel mutations （c. II5G〉T, c.380T〉A, c.263C〉A, and c.818_819insGGGCT）. Among the 22 Chinese patients with CMT1X, the frequency of the GJB1 mutation was 4.5% in transmembrane domain 1 （TM1）, 4.5% in TM2, 27.7% in TM3, 9.1% in TM4, 4.5% in extracellular 1 （EC1）, 27.3% in EC2, 9.1% in intracellular loop, 13.6% in the N-terminal domain, and 4.5% in the C-ternlinal domain. CMTIX with CNS impairment appeared in five （22.7%） of these patients. Conclusions： This study indicated that CNS impairment was not rare in Chinese CMT1X patients. Mutations in the EC2 domain of the GJBI gene were hotspot in Chinese CMT1X patients.展开更多
Charcot-Marie-Tooth disease （CMT）, also known as hereditary motor and sensory neuropathies,comprises a genetically heterogeneous group of inherited peripheral neuropathies. Clinically it is characterized by progress...Charcot-Marie-Tooth disease （CMT）, also known as hereditary motor and sensory neuropathies,comprises a genetically heterogeneous group of inherited peripheral neuropathies. Clinically it is characterized by progressive distal weakness, muscle atrophy, distal sensory loss and loss of deep tendon reflexes. Following electrophysiological criteria, CMT is divided into two main forms：展开更多
We previously found that the K141N mutation in heat shock protein B8 （HSPB8） was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a tr...We previously found that the K141N mutation in heat shock protein B8 （HSPB8） was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a transgenic mouse model bearing the K141N mutation in the human HSPB8 gene, and to determine whether this K141NHSPB8 transgenic mouse model would manifest the clinical phenotype of Charcot-Marie-Tooth disease type 2L, and consequently be suitable for use in studies of disease pathogenesis. Transgenic mice overexpressing K141N HSPB8 were generated using K141N mutant HSPB8 cDNA cloned into a pCAGGS plasmid driven by a human cytomegalovirus expression system. PCR and western blot analysis confirmed integration of the KI41NHSPB8 gene and widespread expression in tissues of the transgenic mice. The K141N HSPB8 transgenic mice exhibited decreased muscle strength in the hind limbs and impaired motor coordination, but no obvious sensory disturbance at 6 months of age by behavioral assessment. Electrophysiological analysis showed that the compound motor action potential amplitude in the sciatic nerve was significantly decreased, but motor nerve conduction velocity remained normal at 6 months of age. Pathological analysis of the sciatic nerve showed reduced myelinated fiber density, notable axonal edema and vacuolar degeneration in K141N HSPB8 transgenic mice, suggesting axonal involvement in the peripheral nerve damage in these animals. These findings indicate that the KI4mHSPB8 transgenic mouse successfully models Charcot-Marie-Tooth disease type 2L and can be used to study the pathogenesis of the disease.展开更多
分析X-连锁腓骨肌萎缩症1型(X-linked Charcot-Marie-Tooth disease type 1,CMT1X)一家系的临床表现、电生理与突变基因特点。该家系为两代4人,共有2例CMT1X患者。先证者12岁起病,先证者母亲40岁起病,两者均表现为进行性肢体无力、萎缩...分析X-连锁腓骨肌萎缩症1型(X-linked Charcot-Marie-Tooth disease type 1,CMT1X)一家系的临床表现、电生理与突变基因特点。该家系为两代4人,共有2例CMT1X患者。先证者12岁起病,先证者母亲40岁起病,两者均表现为进行性肢体无力、萎缩,行走不稳。神经电生理检查均提示:四肢多发感觉运动神经损害(轴索损害为主并脱髓鞘);多发肌肉呈神经源性损害。突变基因分析,先证者存在缝隙连接蛋白B1(gap junction protein Bata-1,GJB1)基因c.283 G>T(p.V95L)半合子突变,先证者母亲存在GJB1基因c.283 G>T(p.V95L),杂合突变。CMT1X是第二常见的腓骨肌萎缩症(Charcot-Marie-Tooth disease,CMT)类型,由GJB1基因突变引起,临床表现为进行性发展的周围神经病可合并中枢神经系统损害,基因检测有助诊断。展开更多
基金This study was supported by a grant from the National Science Foundation of China （No. 81471185）.
文摘Background： X-linked Charcot-Marie-Tooth type 1 （CMT1 X） disease is one of the most common forms of inherited neuropathy caused by mutations in the gap junction beta-1 protein （GJB1） gene （also known as connexin 32）. This study presented the clinical and genetic features of a series of Chinese patients with GJB1 gene mutations. Methods： A total of 22 patients from unrelated families, who were referred to Department of Neurology, Peking University First Hospital from January 2005 to January 2016, were identified with GJBI mutations. Their clinical records and laboratory findings were retrospectively collected and reviewed. Mutations in the GJB1 gene were analyzed by targeted next-generation sequencing （NGS）. Nucleotide alternations were confirnled with Sanger sequencing. Results： The CMT1X patients predominantly showed distal muscle weakness of lower limbs with mild sensory disturbance. The mean age of onset was 15.6 ± 8.7 years （ranging from 1 year to 42 years）. The sudden onset of cerebral symptoms appeared in four patients （ 18.2%）： two were initial symptoms. One case had constant central nervous system （CNS） signs. There were 19 different heterozygous mutations, including 15 known mutations and tbur novel mutations （c. II5G〉T, c.380T〉A, c.263C〉A, and c.818_819insGGGCT）. Among the 22 Chinese patients with CMT1X, the frequency of the GJB1 mutation was 4.5% in transmembrane domain 1 （TM1）, 4.5% in TM2, 27.7% in TM3, 9.1% in TM4, 4.5% in extracellular 1 （EC1）, 27.3% in EC2, 9.1% in intracellular loop, 13.6% in the N-terminal domain, and 4.5% in the C-ternlinal domain. CMTIX with CNS impairment appeared in five （22.7%） of these patients. Conclusions： This study indicated that CNS impairment was not rare in Chinese CMT1X patients. Mutations in the EC2 domain of the GJBI gene were hotspot in Chinese CMT1X patients.
文摘Charcot-Marie-Tooth disease （CMT）, also known as hereditary motor and sensory neuropathies,comprises a genetically heterogeneous group of inherited peripheral neuropathies. Clinically it is characterized by progressive distal weakness, muscle atrophy, distal sensory loss and loss of deep tendon reflexes. Following electrophysiological criteria, CMT is divided into two main forms：
基金funded by the National Natural Science Foundation of China,No.81071001,30900805
文摘We previously found that the K141N mutation in heat shock protein B8 （HSPB8） was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a transgenic mouse model bearing the K141N mutation in the human HSPB8 gene, and to determine whether this K141NHSPB8 transgenic mouse model would manifest the clinical phenotype of Charcot-Marie-Tooth disease type 2L, and consequently be suitable for use in studies of disease pathogenesis. Transgenic mice overexpressing K141N HSPB8 were generated using K141N mutant HSPB8 cDNA cloned into a pCAGGS plasmid driven by a human cytomegalovirus expression system. PCR and western blot analysis confirmed integration of the KI41NHSPB8 gene and widespread expression in tissues of the transgenic mice. The K141N HSPB8 transgenic mice exhibited decreased muscle strength in the hind limbs and impaired motor coordination, but no obvious sensory disturbance at 6 months of age by behavioral assessment. Electrophysiological analysis showed that the compound motor action potential amplitude in the sciatic nerve was significantly decreased, but motor nerve conduction velocity remained normal at 6 months of age. Pathological analysis of the sciatic nerve showed reduced myelinated fiber density, notable axonal edema and vacuolar degeneration in K141N HSPB8 transgenic mice, suggesting axonal involvement in the peripheral nerve damage in these animals. These findings indicate that the KI4mHSPB8 transgenic mouse successfully models Charcot-Marie-Tooth disease type 2L and can be used to study the pathogenesis of the disease.
