[Carnitine in the treatment of methylmalonic aciduria (MMA)]

Carnitine metabolism was studied and a therapeutic trial with L-carnitine was undertaken in 3 patients with methylmalonic aciduria. Prior to carnitine therapy, the concentration of free carnitine was diminished and the contribution of acylated carnitine to total carnitine was increased in both plasma and urine. During a metabolic crisis, in a patient the intravenous administration of L-carnitine greatly increased, the urinary excretion of acylcarnitine and the plasma concentration of methylmalonic acid fell. In all 3 patients, the chronic oral administration of L-carnitine resulted in the normalisation of the plasma free carnitine concentrations and an increased urinary excretion of carnitine esters. One patient clearly showed clinical improvement under carnitine therapy. The administration of L-carnitine to patients with methylmalonic aciduria results in an increased elimination of toxic propionyl groups and thus to a regeneration of intramitochondrial CoA. In conjunction with appropriate dietary measures, this may improve the metabolic situation of these patients.