Maple Syrup Urine Disease (MSUD)


Maple Syrup Urine Disease (MSUD) 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 it’s name.


The condition is diagnosed during newborn screening via the heel prick test taken 48-72 hours after birth.


1:150,000 babies born in Australia and New Zealand.

Treatment for MSUD

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

Maple Syrup Urine Disease (MSUD) Handbook

MSUD – Fruit and Veg Counting Lists

MSUD – General Protein Counting Lists

TEMPLE Resource – MSUD Book

TEMPLE Resource – MSUD Video