Reviewed December 2008
What is the official name of the DBT gene?
The official name of this gene is “dihydrolipoamide branched chain transacylase E2.”
DBT is the gene's official symbol. The DBT gene is also known by other names, listed below.
What is the normal function of the DBT gene?
The DBT gene provides instructions for making part of an enzyme complex (a group of enzymes that work together) called branched-chain alpha-keto acid dehydrogenase, or BCKD. Specifically, the protein produced from the DBT gene forms a critical part of the enzyme complex called the E2 component.
The BCKD enzyme complex is responsible for one step in the normal breakdown of three protein building blocks (amino acids). These amino acids—leucine, isoleucine, and valine—are obtained from the diet. They are present in many kinds of food, particularly protein-rich foods such as milk, meat, and eggs. The BCKD enzyme complex is active in mitochondria, which are specialized structures inside cells that serve as energy-producing centers. The breakdown of leucine, isoleucine, and valine produces molecules that can be used for energy.
How are changes in the DBT gene related to health conditions?
- maple syrup urine disease - caused by mutations in the DBT gene
More than 30 mutations in the DBT gene have been identified in people with maple syrup urine disease, most often in individuals with mild variants of the disorder. Mutations in the DBT gene include changes in single DNA building blocks (base pairs) and insertions or deletions of a small amount of DNA in the DBT gene.
Mutations in the DBT gene disrupt the normal function of the E2 component, preventing the BCKD enzyme complex from effectively breaking down leucine, isoleucine, and valine. As a result, these amino acids and their byproducts build up in the body. This accumulation is toxic to cells and tissues, particularly in the nervous system. The buildup of these substances can lead to seizures, developmental delay, and the other medical problems associated with maple syrup urine disease.
Where is the DBT gene located?
Cytogenetic Location: 1p31
Molecular Location on chromosome 1: base pairs 100,652,477 to 100,715,408
The DBT gene is located on the short (p) arm of chromosome 1 at position 31.
More precisely, the DBT gene is located from base pair 100,652,477 to base pair 100,715,408 on chromosome 1.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
Where can I find additional information about DBT?
You and your healthcare professional may find the following resources about DBT helpful.
Educational resources - Information pages
- Basic Neurochemistry (sixth edition, 1998): Major pathways of branched-chain amino acid metabolism (figure) (http://www.ncbi.nlm.nih.gov/books/NBK20436/figure/A3097/)
- Basic Neurochemistry (sixth edition, 1998): Maple syrup urine disease was the first congenital defect of branched-chain amino acid catabolism to be described (http://www.ncbi.nlm.nih.gov/books/NBK28225/)
- Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1319/)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for DBT (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=1629%5Bgeneid%5D)
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=((DBT%20AND%20maple%20syrup%20urine%20disease%5BTIAB%5D)%20OR%20(dihydrolipoamide%20branched%20chain%20transacylase%5BTIAB%5D))%20OR%20((dihydrolipoamide%20branched%20chain%20transacylase%5BTIAB%5D)%20OR%20(MSUD2%5BTIAB%5D)%20OR%20(E2%20%5Btiab%5D%20AND%20BCKD%20%5Btiab%5D)%20OR%20(E2%20%5Btiab%5D%20AND%20branched-chain%20alpha-ketoacid%20dehydrogenase%20complex%20%5Btiab%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%203600%20days%22%5Bdp%5D)
- OMIM - Genetic disorder catalog (http://omim.org/entry/248610)
Research Resources - Tools for researchers
- Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/1629)
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=1629)
- HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=2698)
What other names do people use for the DBT gene or gene products?
- dihydrolipoamide branched chain transacylase (E2 component of branched chain keto acid dehydrogenase complex; maple syrup urine disease)
- E2 component of branched chain keto acid dehydrogenase complex
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
What glossary definitions help with understanding DBT?
developmental delay ;
nervous system ;
You may find definitions for these and many other terms in the Genetics Home Reference
- Chi CS, Tsai CR, Chen LH, Lee HF, Mak BS, Yang SH, Wang TY, Shu SG, Chen CH. Maple syrup urine disease in the Austronesian aboriginal tribe Paiwan of Taiwan: a novel DBT (E2) gene 4.7 kb founder deletion caused by a nonhomologous recombination between LINE-1 and Alu and the carrier-frequency determination. Eur J Hum Genet. 2003 Dec;11(12):931-6. (http://www.ncbi.nlm.nih.gov/pubmed/14508502?dopt=Abstract)
- Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/1629)
- Flaschker N, Feyen O, Fend S, Simon E, Schadewaldt P, Wendel U. Description of the mutations in 15 subjects with variant forms of maple syrup urine disease. J Inherit Metab Dis. 2007 Nov;30(6):903-9. Epub 2007 Oct 8. (http://www.ncbi.nlm.nih.gov/pubmed/17922217?dopt=Abstract)
- Henneke M, Flaschker N, Helbling C, Müller M, Schadewaldt P, Gärtner J, Wendel U. Identification of twelve novel mutations in patients with classic and variant forms of maple syrup urine disease. Hum Mutat. 2003 Nov;22(5):417. (http://www.ncbi.nlm.nih.gov/pubmed/14517957?dopt=Abstract)
- Nellis MM, Danner DJ. Gene preference in maple syrup urine disease. Am J Hum Genet. 2001 Jan;68(1):232-7. Epub 2000 Dec 7. (http://www.ncbi.nlm.nih.gov/pubmed/11112664?dopt=Abstract)
- Quental S, Macedo-Ribeiro S, Matos R, Vilarinho L, Martins E, Teles EL, Rodrigues E, Diogo L, Garcia P, Eusébio F, Gaspar A, Sequeira S, Furtado F, Lança I, Amorim A, Prata MJ. Molecular and structural analyses of maple syrup urine disease and identification of a founder mutation in a Portuguese Gypsy community. Mol Genet Metab. 2008 Jun;94(2):148-56. doi: 10.1016/j.ymgme.2008.02.008. Epub 2008 Apr 2. (http://www.ncbi.nlm.nih.gov/pubmed/18378174?dopt=Abstract)
- Rodríguez-Pombo P, Navarrete R, Merinero B, Gómez-Puertas P, Ugarte M. Mutational spectrum of maple syrup urine disease in Spain. Hum Mutat. 2006 Jul;27(7):715. (http://www.ncbi.nlm.nih.gov/pubmed/16786533?dopt=Abstract)
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.