Rhabdomyolysis with exercise intolerance and high CK (often high lactate) with ragged red fibers
Rhabdomyolysis and exercise intolerance - MTCYB, CPT2, ETFDH, LPIN1
Clinical Features
Rhabdomyolysis is a common clinical syndrome that results from acute muscle fiber necrosis with leakage of muscle constituents into blood. Myoglobinuria is the most significant consequence, leading to acute renal failure (ARF) in 15% of patients with rhabdomyolysis. Rhabdomyolysis occurs from inherited diseases, toxins, muscle compression, overexertion, or inflammatory processes, among other disorders. In some cases, no cause is found.
Genetic Information
Many of the reported cases of familial myoglobinuria are related to carnitine palmitoyltransferase deficiency, caused by mutations in the CPT2 gene. Myoglobinuria also occurs with deficiency of muscle phosphorylase (McArdle disease), caused by mutations in the gene encoding muscle glycogen phosphorylase (PYGM). Mitochondrial deficiency might also lead to rhabdomyolysis. Most frequently, mutations in the mtDNA Cytb gene were identified, however patients were reported carrying mutations in mtDNA COI-III, ND and tRNA genes.
Prevalence
Rhabdomyolysis itself is relatively frequent, however the exact prevalence of the disease with mitochondrial origin is not known.
Diagnostic
Indication
Method
Mutation analysis for mtDNA Cytb, tRNA, COI-III or ND mutations by DNA sequencing (depending on the activities of the respiratory chain enzymes in muscle)
Sample Requirement
Muscle DNA (for tRNA mutations EDTA-blood)
Duration
2 - 5 weeks