Diagnosis of medium chain acyl CoA dehydrogenase deficiency by measurement of cis-4-decenoic acid in dried blood spots.

Using gas chromatography-mass spectrometry (GC-MS), with selected ion monitoring, a method for measurement of cis-4-decenoate in dried blood spots was developed. Using this assay, the concentration of cis-4-decenoate was determined in blood spots taken from a control population, seven children with medium chain acyl CoA dehydrogenase (MCAD) deficiency who were well at the time of sample collection and an asymptomatic sibling of a child with MCAD deficiency. cis-4-Decenoate was elevated, above the control range, in all the children with MCAD deficiency and in the previously undiagnosed sibling. It is concluded that measurement of cis-4-decenoate in dried blood spots provides a reliable and sensitive test for MCAD deficiency, that could be used in screening programmes.