Increased frequency of rhabdomyolysis in familial dysautonomia

Introduction:Familial dysautonomia (FD; OMIM # 223900) is an autosomal recessive disease with features of impaired pain and temperature perception and lack of functional muscle spindles. After 3 FD patients presented with rhabdomyolysis in a short time span, we aimed to determine the frequency of rhabdomyolysis is this population. Methods: This study was a retrospective chart review of 665 FD patients. Results: Eight patients had at least 1 episode of rhabdomyolysis. Two patients had 2 episodes. The average incidence of rhabdomyolysis in FD was 7.5 per 10,000 person-years. By comparison, the average incidence with statins has been reported to be 0.44 per 10,000 person-years. Mean maximum creatine kinase (CK) level was 32,714±64,749 U/L. Three patients had hip magnetic resonance imaging showing gluteal hyperintensities. Conclusions: Patients with FD have an increased incidence of rhabdomyolysis. We hypothesize that this may result from a combination of absent functional muscle spindles and muscle mitochondrial abnormalities.