It is caused by a deficiency of branched-chain alpha-ketoacid dehydrogenase complex (BCKDC), the second enzyme of the metabolic pathway of the three BCAAs, leucine, isoleucine, and valine. It is characterized by psychomotor delay, feeding problems, and a maple syrup odor of the urine.
What is the pathophysiology of maple syrup urine disease?
Pathophysiology. MSUD is a metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKAD), leading to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products (ketoacids) in the blood and urine.
Is maple syrup urine disease a metabolic disorder?
Maple syrup urine disease (MSUD) is a life-threatening metabolic disorder. Metabolic disorders are conditions in which your body can’t function normally because it can’t properly convert food to energy to keep your body healthy.
What is the biochemical cause of MSUD?
MSUD is caused by changes (mutations) in one of three different genes: BCKDHA, BCKDHB and DBT. Mutations in these genes result in absent or decreased activity of human branched-chain alpha-ketoacid dehydrogenase complex (BCKAD) enzymes.
What body systems are affected by MSUD?
People with this condition cannot break down the amino acids leucine, isoleucine, and valine. This leads to a buildup of these chemicals in the blood. In the most severe form, MSUD can damage the brain during times of physical stress (such as infection, fever, or not eating for a long time).
How does MSUD cause hypoglycemia?
Speculation: Hypoglycemia associated with MSUD appears to be related to a defect in gluconeogenesis from amino acids, which cannot be accounted for by abnormalities of the ratelimiting gluconeogenic enzymes or hyperinsulinemia.
What chromosome is MSUD on?
MSUD is an autosomal recessive disorder resulting from homozygous or compound heterozygous mutations in one of three genes encoding the aforementioned subunits of the BCKDH complex, also known as BCKDC. MSUD type IA results from mutations in BCKDHA (chromosome 19q13.
How do you manage MSUD?
The two main approaches to the treatment of maple syrup urine disease (MSUD) include (1) long-term daily dietary management and (2) treatment of episodes of acute metabolic decompensation. The mainstay in the treatment of maple syrup urine disease is dietary restriction of branched-chain amino acids (BCAAs).
Why do I randomly smell maple syrup?
Maple syrup urine disease (MSUD) is a disorder in which the body cannot break down certain parts of proteins. The urine of people with this condition can smell like maple syrup.
What type of mutation is MSUD?
Maple syrup urine disease (MSUD) is a rare autosomal recessive metabolic disorder. This disorder is usually caused by mutations in any one of the genes; BCKDHA, BCKDHB and DBT, which represent E1α, E1β and E2 subunits of the branched-chain α-keto acid dehydrogenase (BCKDH) complex, respectively.
