Isobutyryl-CoA dehydrogenase (IBD) deficiency is a condition that disrupts the breakdown of certain proteins. Normally, proteins from food are broken down into parts called amino acids. Amino acids can be further processed to provide energy for growth and development. People with IBD deficiency have inadequate levels of an enzyme that helps break down a particular amino acid called valine.
Most people with IBD deficiency are asymptomatic, which means they do not have any signs or symptoms of the condition. A few children with IBD deficiency have developed features such as a weakened and enlarged heart (dilated cardiomyopathy), weak muscle tone (hypotonia), and developmental delay. This condition may also cause low numbers of red blood cells (anemia) and very low blood levels of carnitine, which is a natural substance that helps convert certain foods into energy. The range of signs and symptoms associated with IBD deficiency remains unclear because very few affected individuals have been reported.
IBD deficiency is a rare disorder; approximately 22 cases have been reported in the medical literature.
Mutations in the ACAD8 gene cause IBD deficiency. This gene provides instructions for making the IBD enzyme, which is involved in breaking down valine. ACAD8 gene mutations reduce or eliminate the activity of the IBD enzyme. As a result, valine is not broken down properly. Impaired processing of valine may lead to reduced energy production and the features of IBD deficiency.
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Other Names for This Condition
- Deficiency of isobutyryl-CoA dehydrogenase
- IBD deficiency
- Isobutyryl-coenzyme A dehydrogenase deficiency
Additional Information & Resources
Genetic Testing Information
Genetic and Rare Diseases Information Center
Catalog of Genes and Diseases from OMIM
Scientific Articles on PubMed
- Koeberl DD, Young SP, Gregersen NS, Vockley J, Smith WE, Benjamin DK Jr, An Y, Weavil SD, Chaing SH, Bali D, McDonald MT, Kishnani PS, Chen YT, Millington DS. Rare disorders of metabolism with elevated butyryl- and isobutyryl-carnitine detected by tandem mass spectrometry newborn screening. Pediatr Res. 2003 Aug;54(2):219-23. Epub 2003 May 7. Citation on PubMed
- Nguyen TV, Andresen BS, Corydon TJ, Ghisla S, Abd-El Razik N, Mohsen AW, Cederbaum SD, Roe DS, Roe CR, Lench NJ, Vockley J. Identification of isobutyryl-CoA dehydrogenase and its deficiency in humans. Mol Genet Metab. 2002 Sep-Oct;77(1-2):68-79. Citation on PubMed
- Oglesbee D, He M, Majumder N, Vockley J, Ahmad A, Angle B, Burton B, Charrow J, Ensenauer R, Ficicioglu CH, Keppen LD, Marsden D, Tortorelli S, Hahn SH, Matern D. Development of a newborn screening follow-up algorithm for the diagnosis of isobutyryl-CoA dehydrogenase deficiency. Genet Med. 2007 Feb;9(2):108-16. Citation on PubMed
- Pedersen CB, Bischoff C, Christensen E, Simonsen H, Lund AM, Young SP, Koeberl DD, Millington DS, Roe CR, Roe DS, Wanders RJ, Ruiter JP, Keppen LD, Stein Q, Knudsen I, Gregersen N, Andresen BS. Variations in IBD (ACAD8) in children with elevated C4-carnitine detected by tandem mass spectrometry newborn screening. Pediatr Res. 2006 Sep;60(3):315-20. Epub 2006 Jul 20. Citation on PubMed
- Roe CR, Cederbaum SD, Roe DS, Mardach R, Galindo A, Sweetman L. Isolated isobutyryl-CoA dehydrogenase deficiency: an unrecognized defect in human valine metabolism. Mol Genet Metab. 1998 Dec;65(4):264-71. Citation on PubMed
- Sass JO, Sander S, Zschocke J. Isobutyryl-CoA dehydrogenase deficiency: isobutyrylglycinuria and ACAD8 gene mutations in two infants. J Inherit Metab Dis. 2004;27(6):741-5. Citation on PubMed
- Yoo EH, Cho HJ, Ki CS, Lee SY. Isobutyryl-CoA dehydrogenase deficiency with a novel ACAD8 gene mutation detected by tandem mass spectrometry newborn screening. Clin Chem Lab Med. 2007;45(11):1495-7. Citation on PubMed