WHAT IS MAPLE SYRUP URINE DISEASE?
CAUSES OF DISEASE
Maple syrup urine disease (MSUD) is caused by a gene defect. This is caused by mutations in the BCKDHA, BCKDHB and DBT genes. These three genes provide instructions for making proteins that work together as a complex. The protein complex is essential for breaking down the amino acids leucine, isoleucine, and valine, which are present in many kinds of food. particularly protein-rich foods such as milk, meat and eggs.
Mutations in any of these three genes reduce or eliminate the function of the protein complex, preventing the normal breakdown of leucine, isoleucine, and valine. As a result, these amino acids and their byproducts build up in the body. Because high levels of these substances are toxic to the brain and other organs, their accumulation leads to the serious health problems associated with maple syrup urine disease. 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. Some types of MSUD are mild or come and go. Even in the mildest form, repeated periods of physical stress can cause intellectual disability and high levels of leucine. |
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HOW DO PEOPLE INHERIT MAPLE SYRUP URINE DISEASE?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the conditon.
SYMPTOMS OF DISEASE
- Avoiding food
- Coma
- Feeding difficulties
- Lethhargy
- Seizures
- Urine that smells like maple syrup
- Vomiting
OTHER NAMES FOR MAPLE SYRUP URINE DISEASE
- BCKD deficiency
- Branched-chain alpha-keto acid dehydrogenase deficiency
- Branched-chain ketoaciduria
- Ketoacidemia
- MSUD