Interpretation of Acylcarnitine Analysis Results

The analysis of acylcarnitines in plasma or blood spot samples by tandem mass spectrometry will detect all 15 defects of mitochondrial fatty acid beta-oxidation, although false negative results may occur in well-fed, non-fasting patients. Moreover, more than 20 organic acidemias can be detected by this methodological approach. An acylcarnitine profile should be part of the work-up of patients presenting with rhabdomyolysis and/or hypoglycemia and adults with an unexplained leukoencephalopathy. Cases with abnormal acylcarnitines require an analysis of urine organic acids as well as enzyme activity evaluation and molecular investigations to confirm the inherited defect.