X-linked myopathy with excessive autophagy is a rare disorder caused by a mutation in the vacuolar ATPase assembly factor gene which causes slowly progressive early onset proximal weakness and loss of ambulation by the age of 50-70 years. Electrodiagnostic (EDx) testing usually shows widespread complex repetitive and myotonic discharges, even in muscles unaffected clinically. We report a 65-year-old man who presented with progressive proximal weakness since his teenage years. Extensive workup over 30 years revealed inconclusive EDx and muscle histopathology findings. The diagnosis was finally made with genetic testing. Subsequent neuromuscular ultrasound was more informative of disease severity than repeat EDx and directed a muscle biopsy that showed an autophagic vacuolar myopathy and the novel identification of vacuoles in capillary endothelial cells. Although genetic testing is required for confirmation, in milder cases of X-linked myopathy with excessive autophagy, neuromuscular ultrasound may aid in diagnosis even when EDx findings are inconclusive.
Keyphrases
- late onset
- early onset
- cell death
- muscular dystrophy
- endoplasmic reticulum stress
- weight gain
- endothelial cells
- signaling pathway
- multiple sclerosis
- oxidative stress
- magnetic resonance imaging
- skeletal muscle
- genome wide
- ultrasound guided
- copy number
- single cell
- computed tomography
- transcription factor
- fine needle aspiration
- contrast enhanced ultrasound
- myasthenia gravis