Authors: Olimpia Musumeci Stefen Brady Carmelo Rodolico Annamaria Ciranni Federica Montagnese M’hammed Aguennouz Richard Kirk Elizabeth Allen Richard Godfrey Sara Romeo Elaine Murphy Shamima Rahman Ros Quinlivan Antonio Toscano
Publish Date: 2014/09/30
Volume: 261, Issue: 12, Pages: 2424-2428
Abstract
Muscle βenolase deficiency is a very rare inherited metabolic myopathy caused by an enzymatic defect of distal glycolysis So far the condition has been described in only one patient with mutations in ENO3 in a compound heterozygous state who presented with exercise intolerance postexercise myalgia and mild hyperCKemia but no pigmenturia We describe two men one Italian and one Turkish with consanguineous parents who complained of several episodes of intense myalgia cramps generalized muscle tenderness and dark urine No other family members reported similar symptoms In both cases there was a very mild rise in lactate during a forearm exercise test Muscle biopsy showed minimal changes with no lipid or glycogen accumulation Biochemical studies on muscle tissue demonstrated a marked reduction of muscle βenolase activity 20 and 10 of residual activity respectively Molecular genetic analysis of ENO3 gene revealed two novel homozygous missense mutations pAsn151Ser and pGlu187Lys Both mutations segregated as expected in the two families Although quite rare muscle βenolase deficiency should be considered in the differential diagnosis of patients presenting with recurrent rhabdomyolysis It may present also with a more severe phenotype than previously thought
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