Reviewed February 2006
What is the official name of the DLD gene?
The official name of this gene is “dihydrolipoamide dehydrogenase.”
DLD is the gene's official symbol. The DLD gene is also known by other names, listed below.
What is the normal function of the DLD gene?
The DLD gene provides instructions for making a protein called dihydrolipoamide dehydrogenase. This protein is part of several enzyme complexes (groups of enzymes that work together). These complexes are essential for the breakdown of certain molecules to produce energy in cells. Dihydrolipoamide dehydrogenase forms a subunit called the E3 component that is shared by several enzyme complexes.
Branched-chain alpha-keto acid dehydrogenase, or BCKD, is one of the enzyme complexes that include the E3 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 breakdown of these amino acids produces molecules that can be used for energy.
How are changes in the DLD gene related to health conditions?
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maple syrup urine disease - caused by mutations in the DLD gene
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More than 10 mutations in the DLD gene have been identified in people with maple syrup urine disease. Mutations in this gene are responsible for a variant form of the disorder that includes lactic acidosis, a potentially life-threatening complication caused by the buildup of lactic acid in the body's tissues.
Most DLD mutations change single amino acids in the E3 component of the BCKD enzyme complex. These mutations alter the structure of the E3 component, which prevents the enzyme complex from effectively breaking down valine, isovaline, and leucine. 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 DLD gene located?
Cytogenetic Location: 7q31-q32
Molecular Location on chromosome 7: base pairs 107,318,846 to 107,347,644
The DLD gene is located on the long (q) arm of chromosome 7 between positions 31 and 32.
More precisely, the DLD gene is located from base pair 107,318,846 to base pair 107,347,644 on chromosome 7.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about DLD?
You and your healthcare professional may find the following resources about DLD helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed
- Recent literature
- OMIM
- Genetic disorder catalog
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What other names do people use for the DLD gene or gene products?
- DIA1
- Diaphorase
- dihydrolipoamide dehydrogenase (E3 component of pyruvate dehydrogenase complex, 2-oxo-glutarate complex, branched chain keto acid dehydrogenase complex)
- Dihydrolipoyl dehydrogenase
- DLDH
- DLDH_HUMAN
- E3 component of pyruvate dehydrogenase
- GCSL
- Glycine cleavage system L protein
- LAD
- Lipoamide Dehydrogenase
- Lipoamide reductase
- Lipoamide reductase (NADH)
- Lipoyl Dehydrogenase
- PHE3
- Pyruvate dehydrogenase component E3
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding DLD?
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
healthcare professional.
See How can I find a genetics professional in my area? in the Handbook.