Amino Acid Disorders
Maple Syrup Urine Disease (MSUD)
Definition
Maple syrup urine disease is an autosomal recessive inherited disorder based on a genetic mutation of the branched-chain 2-ketoacid dehydrogenase complex, which is responsible for the metabolism of the essential branched-chain amino acids leucine, isoleucine and valine. This causes an accumulation of these amino acids, along with severe neurological damage. As a result of the toxic metabolites produced the urine has a sweet smell which is the origin of the name maple syrup urine disease.
Diagnosis
The condition is diagnosed during newborn screening via the heel prick test taken 48-72 hours after birth.
Prevalence
1:150,000 babies born in Australia and New Zealand.
Treatment
MSUD is treated using a restricted low-protein diet and amino acid supplement free of branched-chain amino acids.
In the event of early diagnosis (newborn screening) and life-long treatment, most patients are able to remain in good health.
Support Links & Materials
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Argininosuccinic Acidaemia (ASA)
Arginase Deficiency (ARG)