Related Experiment Video
Updated: Feb 21, 2026
Utility of Dissociated Intrinsic Hand Muscle Atrophy in the Diagnosis of Amyotrophic Lateral Sclerosis
Published on: March 4, 2014
Correlation between the CAG repeat size and electrophysiological findings in patients with spinal and bulbar muscular
Hyunjin Kim1, Young-Min Lim1, Eun-Jae Lee1
1Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil Songpa-gu, Seoul, 05505, Republic of Korea.
Introduction:
Spinal and bulbar muscular atrophy (SBMA) is caused by the expansion of a CAG repeat in the androgen receptor gene. The relationship between the CAG repeat size and electrophysiological findings is not completely understood.
Methods:
We retrospectively analyzed 62 SBMA patients to assess the correlation between their CAG repeat size and electrophysiological findings.
Results:
In multiple regression analysis including age at examination and disease duration, we identified a negative correlation between the CAG repeat size and the compound muscle action potential (CMAP) amplitude. No significant correlation was found between the CAG repeat size and sensory nerve action potential (SNAP) amplitude.
Discussion:
Contrary to previous reports of motor- and sensory-dominant phenotypes correlating with CAG repeat sizes, the CAG repeat size was negatively correlated only with CMAP amplitude, and not with SNAP amplitude. Muscle Nerve 57: 683-686, 2018.
More Related Videos
08:22A Robust Polymerase Chain Reaction-based Assay for Quantifying Cytosine-guanine-guanine Trinucleotide Repeats in Fragile X Mental Retardation-1 Gene
Published on: September 16, 2019
06:35In Vivo Electrophysiological Measurement of Compound Muscle Action Potential from the Forelimbs in Mouse Models of Motor Neuron Degeneration
Published on: June 15, 2018