Background：Congenital myasthenic syndromes are a group orrare disorders that are clinically and genetically heterogeneous and caused by mutations in the genes encoding proteins of the neuromuscular junction.Here,we d...Background：Congenital myasthenic syndromes are a group orrare disorders that are clinically and genetically heterogeneous and caused by mutations in the genes encoding proteins of the neuromuscular junction.Here,we described a Chinese family that presented with phenotypes of classic slow-channel congenital myasthenic syndrome （SCCMS）.Methods：Clinical characteristics and electrophysiological features of three patients from a Chinese family were examined,and next-generation sequencing followed by direct sequencing was carried out.Results：The patients revealed variability in clinical and electrophysiological features.However,weakness,scoliosis,and repetitive-compound muscle action potential were found in all affected members in the family.A heterozygous C〉T missense mutation at nucleotide 865 in acetylcholine receptor epsilon-subunit （CHRNE） gene that causes a leucine-to-phenylalanine substitution at position 289 （L289F） was found.Conclusions：We reported a SCCMS family of Chinese origin.In the family,classical clinical phenotype with phenotypic variability among different members was found.Genetic testing could help diagnose this rare disease.展开更多
文摘Background：Congenital myasthenic syndromes are a group orrare disorders that are clinically and genetically heterogeneous and caused by mutations in the genes encoding proteins of the neuromuscular junction.Here,we described a Chinese family that presented with phenotypes of classic slow-channel congenital myasthenic syndrome （SCCMS）.Methods：Clinical characteristics and electrophysiological features of three patients from a Chinese family were examined,and next-generation sequencing followed by direct sequencing was carried out.Results：The patients revealed variability in clinical and electrophysiological features.However,weakness,scoliosis,and repetitive-compound muscle action potential were found in all affected members in the family.A heterozygous C〉T missense mutation at nucleotide 865 in acetylcholine receptor epsilon-subunit （CHRNE） gene that causes a leucine-to-phenylalanine substitution at position 289 （L289F） was found.Conclusions：We reported a SCCMS family of Chinese origin.In the family,classical clinical phenotype with phenotypic variability among different members was found.Genetic testing could help diagnose this rare disease.
文摘提出一种基于符号高阶统计量(HOS,high-order statistics)的MPSK调制信道衰落系数盲估计算法。针对平坦慢衰落信道模型,首先分析了MPSK调制符号高阶统计量特征,证明了MPSK调制符号的M次方符号的值是唯一的,而当1≤M′<M时,调制符号的M′次方符号在复平面上是对称分布的;之后利用此特征推导出MPSK调制阶数、初始相位和衰落系数估计算法。仿真实验表明,信噪比高于12 d B条件下,HOS算法估计性能与目前平坦慢衰落信道盲估计的主流方法 Lloyd-Max算法相同,而算法复杂度为Lloyd-Max算法的1/50,并且在接收样本符号较少的条件下HOS算法的均方误差曲线收敛于最小二乘估计理论下界。
