Myologists from the Institut de Myologie (clinicians from the Service of Neuro-Myology and researchers from the CRM and the Morphology Unit) and the Cochin Hospital in the Paris region report the clinical, histological and molecular data of a patient in whom a variant was identified in the XPNPEP3 gene:
- this mitochondrial gene of nuclear origin is usually responsible for nephropathy.
- in the reported case, a 44-year-old patient was examined for exercise intolerance and recurrent episodes of rhabdomyolysis.
- these were associated with axonal sensory neuropathy and white matter abnormalities on brain MRI.
- muscle examination revealed the presence of ragged red muscle fibres and COX-negative fibres, as well as mitochondrial abnormalities under electron microscopy.
- genetic studies linked this muscle damage to a pathogenic homozygous variant in the XPNPEP3 gene.
This observation broadens the phenotype associated with this mitochondrial gene.
