Diagnosis and therapy of organic acidurias

Organic acidurias are a group of numerous inherited metabolic disorders with an involvement of different pathways of the amino acid, carbohydrate and lipid metabolism. Many diseases have their onset with an acute metabolic crisis in the newborn period. The most important diagnostic investigation is organic acid analysis of urine by gas chromatography-mass spectrometry. Because specific clinical signs are lacking, a selective screening procedure is recommended. Diagnosis and therapy should be aggressive, since prognosis of many disorders is related to early diagnosis and specific therapeutic measures. These include long term management with protein restriction, supplementation with special amino acid mixtures and carnitine. In our experience continuous arteriovenous hemofiltration has turned out to be a very effective detoxification method during acute metabolic crisis of the newborn. Long term follow up and therapy control is very important for the outcome of the patients. Measurement of odd long chain fatty acids (OLCFA) in erythrocyte membranes has proved to be a good control parameter of the metabolic condition of children with disorders of the branched-chain amino acid metabolism.