The ACAD8 gene (11q25) encodes isobutyryl Co-A dehydrogenase, which catalyzes the third step of the degradation of the branched chain amino acid valine [6,7]. ACAD8 is a member of the Acyl-coenzyme A (CoA) dehydrogenases (ACADs) family of mitochondrial enzymes that catalyze the first dehydrogenation step in the beta-oxidation of fatty acyl-CoA derivatives . Fatty acids provide important respiratory fuel for many tissues, including heart, skeletal muscle, brown adipose tissue, kidney, and liver, as is evident in individuals with defects in any of the ACAD family members. The mitochondrial beta-oxidation pathway is a cycle of 4 sequential reactions in which the fatty acid substrate is shortened by 2 carbon atoms with each cycle, releasing an acetyl-CoA molecule that can then be used in the tricarboxylic acid cycle or for ketogenesis.
- 1. Roe et al. Isolated isobutyryl-CoA dehydrogenase deficiency: an unrecognized defect in human valine metabolism. Molec. Genet. Metab. 1998, 65:264-271.
- 2. Oglesbee et al. Development of a newborn screening follow-up algorithm for the diagnosis of isobutyryl-CoA dehydrogenase deficiency. Genet. Med. 2007, 9: 108-116.
- 3. Koeberl et al. Rare disorders of metabolism with elevated butyryl- and isobutyryl-carnitine detected by tandem mass spectrometry newborn screening. Pediat. Res. 2003, 54: 219-223.
- 4. Sass et al. Isobutyryl-CoA dehydrogenase deficiency: isobutyrylglycinuria and ACAD8 gene mutations in two infants. J. Inherit. Metab. Dis. 2004, 27: 741-745.
- 5. Pedersen et al. Variations in IBD (ACAD8) in children with elevated C4-carnitine detected by tandem mass spectrometry newborn screening. Pediat. Res. 2006, 60: 315-320.
- 6. Nguyen et al. Identification of isobutyryl-CoA dehydrogenase and its deficiency in humans. Molec. Genet. Metab. 2002, 77: 68-79.
- 7. Telford et al. Isolation and characterisation of a cDNA encoding the precursor for a novel member of the acyl-CoA dehydrogenase gene family. Biochim. Biophys. Acta 1999, 1446: 371-376.
- Confirmation of a clinical/biochemical diagnosis of isobutyryl co-A dehydrogenase deficiency
- Carrier testing in females/adults with a family history of isobutyryl co-A dehydrogenase deficiency
Analytical Sensitivity: ~99%
Submit only 1 of the following specimen types
Preferred specimen type: Whole Blood
Type: Whole Blood
Specimen Requirements:In EDTA (purple top) tube:
Infants (<2 years): 2-3 ml
Children (>2 years): 3-5 ml
Older Children & Adults: 5-10 ml
Specimen Collection and Shipping: Refrigerate until time of shipment. Ship sample within 5 days of collection at room temperature with overnight delivery.
Specimen Requirements:OrageneTM Saliva Collection kit (available through EGL) used according to manufacturer instructions.
Specimen Collection and Shipping: Store sample at room temperature. Ship sample within 5 days of collection at room temperature with overnight delivery.