A sensitive and simplified method to analyze free fatty acids in children with mitochondrial beta oxidation disorders using gas chromatography/mass spectrometry and dried blood spots

Abstract

Background: A precise diagnosis of mitochondrial fatty acid beta-oxidation (FAO) disorders can be difficult as several enzymatic reactions are involved.

Methods: Using 5 blood spots on filter paper, each 3 mm in diameter, octanoate, decanoate, cis-4-decenoic acid (C10:1) and cis-5-tetradecenoic acid (C14:1) were measured by one step transmethylation and gas chromatography-mass spectrometry (GC/MS).

Results: In subjects with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency C10:1 was increased. C14:1 was increased in very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency, and both were increased in multiple acyl CoA dehydrogenase (MAD) deficiency.

Conclusions: Free fatty acids (FFAs) can be measured with a small amount of blood sample if selective ion monitoring (SIM) in GC/MS analysis is used. A single microtube was sufficient throughout the procedure prior to injection onto GC/MS.