DBT Gene

Definition:Dihydrolipoamide branched chain transacylase E2, also known as DBT, is a human gene

Chromosome: 1
Position:1p31
Size Of Gene: 62932 bp (100425066 to100487997)
No Exons : 11
Description

The branched-chain alpha-keto acid dehydrogenase complex (BCKD) is an inner-mitochondrial enzyme complex involved in the breakdown of the branched-chain amino acids isoleucine, leucine, and valine. The BCKD complex is thought to be composed of a core of 24 transacylase (E2) subunits, and associated decarboxylase (E1), dehydrogenase (E3), and regulatory subunits. This gene encodes the transacylase (E2) subunit. Mutations in this gene result in maple syrup urine disease, type 2. Alternatively spliced transcript variants have been described, but their biological validity has not been determined.

Function:

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 made by the DBT gene forms an essential 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.

Disease:

More than 25 mutations in the DBT gene have been identified in people with maple syrup urine disease, most often in individuals with milder 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. These mutations disrupt the normal function of the E2 component, preventing the BCKD enzyme complex from breaking down leucine, isoleucine, and valine. As a result, these amino acids and their byproducts build up in the body. Because this accumulation is toxic to tissues and organs, it leads to the signs and symptoms of maple syrup urine disease.

Short Introduction to Maple Syrup Urine Disease (MSUD)