title: Genotype-phenotype correlation in Chinese patients with spinal and bulbar muscular atrophy.
abstract: Spinal and bulbar muscular atrophy (SBMA) is an X-linked recessive motor neuron disease characterized by slowly progressive weakness and atrophy of proximal limbs and bulbar muscles. To assess the genotype-phenotype correlation in Chinese patients, we identified 155 patients with SBMA and retrospectively examined available data from laboratory tests and neurophysiological analyses. Correlations between genotype and phenotype were analyzed. There was an inverse correlation between the length of CAG repeats and age at first muscle weakness (p<0.0001). The serum creatine kinase level showed a significant inverse correlation with disease duration and the age at examination (p=0.019 and p=0.004, respectively). Unlike previous classification of motor- and sensory-dominant phenotypes, all findings of nerve conduction, except the amplitudes of median nerve compound motor action potential, were positively correlated to the length of CAG repeats. A significant decline in sensory nerve action potential amplitudes may assist differential diagnosis of SBMA.
authors: Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.
authors: Wang
authors: W
authors: Ni
authors: Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China; Department of Neurology and Institute of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
authors: Sheng
authors: S
authors: Chen
authors: Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Kai
authors: K
authors: Qiao
authors: Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.
authors: Ning
authors: N
authors: Wang
authors: Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China; Department of Neurology and Institute of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Zhi-Ying
authors: ZY
authors: Wu
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D002681:China; D004576:Electromyography; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009134:Muscular Atrophy, Spinal / Q000175:diagnosis* / Q000235:genetics*; D009431:Neural Conduction; D010641:Phenotype; D012189:Retrospective Studies; D019680:Trinucleotide Repeat Expansion; D055815:Young Adult