Genotype-phenotype correlation in Chinese patients with spinal and bulbar muscular atrophy

Wang Ni; Sheng Chen; Kai Qiao; Ning Wang; Zhi-Ying Wu

doi:10.1371/journal.pone.0122279

Genotype-phenotype correlation in Chinese patients with spinal and bulbar muscular atrophy

PLoS One. 2015 Mar 26;10(3):e0122279. doi: 10.1371/journal.pone.0122279. eCollection 2015.

Authors

Wang Ni¹, Sheng Chen², Kai Qiao³, Ning Wang¹, Zhi-Ying Wu⁴

Affiliations

¹ Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.
² 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.
³ Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
⁴ 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.

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Age of Onset
Aged
China
Electromyography
Genetic Association Studies*
Genotype*
Humans
Male
Middle Aged
Muscular Atrophy, Spinal / diagnosis*
Muscular Atrophy, Spinal / genetics*
Neural Conduction
Phenotype*
Retrospective Studies
Trinucleotide Repeat Expansion*
Young Adult

Grants and funding

This work was supported by the grant from the National Natural Science Foundation to WZY (81125009, Beijing), http://www.nsfc.gov.cn/. The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.