Organic acidemias complications

Carnitine deficiency complicates HMG-CoA lyase deficiency and other inborn errors of metabolism, which results in organic acidemia. L-Camitine or P-hydroxy-y-trimethylammonium butyrate is a carrier molecule that transports long-chain fatty acids across the inner mitochondrial membrane for subsequent P-oxi-dation. L-Carnitine also facilitates removal of toxic metabolic intermediates or xenobiotics via urinary excretion of their acyl carnitine derivatives. Indeed, individuals with HMG-CoA lyase deficiency have been shown to excrete 3-methylgluatarylcamitine (Roe et al., 1986). In the absence of ketogenesis, the formation of the acyl carnitine derivative of 3-hydroxy-3-methylglutarate from HMG-CoA also serves to regenerate free CoA in the mitochondria and permits continued P-oxidation of fatty acids. 

Another complication of organic acidemias is renal tubular acidosis with hyperuricemia leading to chronic renal impairment and eventually to renal failure [7,13, 24] (Box 17.2). This appears to be especially prominent in individuals with MMA however, renal disease and failure has been reported in both newborns and adults with propionic acidemia [36-38]. Renal histology... 

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