BCKDHA
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Gene summaries condense public reference material; disease links and population data change as databases are updated. Clinical decisions belong with your care team.
branched chain keto acid dehydrogenase E1 subunit alpha
Normal Function
Health Conditions Related to Genetic Changes
Maple syrup urine disease
More than 80 mutations in the BCKDHA gene have been identified in people with maple syrup urine disease. These mutations most often cause the severe, classic form of the disorder, which becomes apparent soon after birth. Maple syrup urine disease gets its name from the distinctive sweet odor of affected infants' urine. It is also characterized by poor feeding, vomiting, lack of energy (lethargy), abnormal movements, and delayed development.
Most BCKDHA mutations change single amino acids in the alpha subunit of the BCKD enzyme complex. In the Old Order Mennonite population, where maple syrup urine disease occurs frequently, the most common mutation replaces the amino acid tyrosine with the amino acid asparagine at position 438 (written as Tyr438Asn or Y438N).
Mutations in the BCKDHA gene disrupt the normal function of the BCKD enzyme complex, preventing it 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 health problems associated with maple syrup urine disease.
More About This Health ConditionRelated Conditions
Maple syrup urine disease
Health Conditions Related to Genetic Changes
More than 80 mutations in the BCKDHA gene have been identified in people with maple syrup urine disease. These mutations most often cause the severe, classic form of the disorder, which becomes apparent soon after birth. Maple syrup urine disease gets its name from the distinctive sweet odor of affected infants' urine. It is also characterized by poor feeding, vomiting, lack of energy (lethargy), abnormal movements, and delayed development.
Most BCKDHA mutations change single amino acids in the alpha subunit of the BCKD enzyme complex. In the Old Order Mennonite population, where maple syrup urine disease occurs frequently, the most common mutation replaces the amino acid tyrosine with the amino acid asparagine at position 438 (written as Tyr438Asn or Y438N).
Mutations in the BCKDHA gene disrupt the normal function of the BCKD enzyme complex, preventing it 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 health problems associated with maple syrup urine disease.