Without acyl CoA dehydrogenase to initiate the first step of mitochondrial beta-oxidation, your ability to metabolize fats is inhibited (1). That is, the enzyme—one of four depending on fatty acid chain lengths—catalyzes the formation of the double bond between alpha- and beta-carbons, which then are degraded to two-carbon acetyl CoA units (1p159).
Because the body relies on the production of acetyl CoA from its storage of fat for energy, the lack of acetyl CoA dehydrogenase and in its capacity to produce beta-oxidation causes the body to end up in a hypoglycemic (no glucose) and hypoketotic state (no ketones from oxidation of fatty acids) (1p159;2-3).
1. Gropper SS, Smith JL, Groff JL. Advanced Nutrition and Human Metabolism. Belmont, CA: Thomson Wadsworth, 2009.
2. PerkinElmer Genetics. Multiple Acyl-CoA Dehydrogenase Deficiency. Available at: http://www.perkinelmergenetics.com/MultipleAcylCoADehydrogenaseDeficiency.htm.
3. STAR-G. Genetic Fact Sheet for Parents: Fatty Acid Oxidation Disorders. Available at: http://www.newbornscreening.info/Parents/fattyaciddisorders/VLCADD.html.