POPULATION SCREENING FOR MEDIUM-CHAIN ACYL-COA DEHYDROGENASE-DEFICIENCY - ANALYSIS OF MEDIUM-CHAIN FATTY-ACIDS AND ACYLGLYCINES IN BLOOD SPOTS

We have developed methods for the measurement of the medium-chain fatt y acids octanoate, decanoate and cis-4-decenoate and the acylglycines n-hexanoylglycine (HG) and 3-phenylpropionylglycine (PPG) in blood spo ts using gas chromatography and mass spectrometry. Normal ranges were obtained for octanoate and decanoate. HG, PPG and cis-4-decenoic acid were not detected in control blood spots. In blood spots from nine pat ients (including two newborn) with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, all metabolites were present in elevated concentra tions although PPG was close to the detection limits and there was ove rlap for octanoate and decanoate. The lack of detection of cis-4-decen oic acid and HG in controls suggests that these are the metabolites of choice for blood spot identification of infants with MCAD deficiency.