Different electrophysiology patterns in GNE myopathy.

Area of Science:

• Neurology
• Genetics
• Molecular Biology

Background:

• GNE myopathy is a rare distal myopathy linked to mutations in the GNE gene.
• Recent reports suggest some GNE myopathy cases exhibit electrophysiological neurogenic features resembling hereditary motor neuropathy.
• This study aimed to confirm and characterize these rare presentations.

Purpose of the Study:

• To investigate and describe the clinical phenotype and genetic mutations in GNE myopathy patients with apparent neurogenic features.
• To differentiate the observed electrophysiological findings from typical myopathic patterns.

Main Methods:

• Clinical examination and electrophysiological studies (electromyography, electroneurography) were performed on affected individuals.
• Muscle pathology was analyzed to determine the underlying tissue characteristics.
• Next-generation sequencing was employed to identify GNE gene variants.

Main Results:

• Four patients displayed electrophysiological signs suggestive of neuropathy, including absent reflexes and reduced motor potentials.
• Muscle pathology predominantly showed myogenic changes, contrasting with the electrophysiological findings.
• Three novel GNE gene variants (c.2054T>C, c.424G>A, c.944T>C) and two known mutations were identified and cosegregated with the disease.

Conclusions:

• This study supports the existence of rare GNE myopathy cases with distinct neurogenic electrophysiological features.
• These findings highlight the complexity of GNE myopathy diagnosis and underscore the importance of genetic analysis.