Non-GNE Quadriceps Sparing Distal Myopathy in an Iranian Jewish Patient

GNE myopathy is an autosomal-recessive distal myopathy. It is caused by a hypomorphic GNE gene, encoding the rate-limiting enzyme in sialic acid synthesis. This myopathy is prevalent in the Iranian Jewish (IJ) descendants because of a founder mutation GNE: p. M712T. We report a 52-year-old IJ woman who presented with a 20-year history of progressive distal muscle weakness. Physical examination and magnetic resonance imaging revealed lower-extremity weakness and atrophy. Electromyography confirmed myopathy. Genetic testing showed no mutations on the GNE gene. Muscle histochemistry demonstrated no rimmed vacuoles. The analysis of polysialylated neural cell adhesion molecule Western blot pattern was negative. Non-GNE myopathy with quadriceps sparing presentation has been previously described in a few cases of non-IJ descents. To the best of our knowledge, this is the first case of an IJ patient, presenting with quadriceps sparing myopathy, without associated GNE mutations and/or tubule-filamentous inclusions.