What is Maple Syrup Urine Disease (MSUD)?

Maple syrup urine disease is a rare inherited metabolic condition in which the body cannot properly break down certain amino acids, leading to a build-up of harmful substances that can seriously affect the brain if untreated. It gets its name from the distinctive sweet smell the build-up can give to urine and sweat.

It's identified through the newborn heel prick screening test, allowing treatment to begin very early, before serious symptoms develop. Management involves a strict, specialised diet and close monitoring, especially during illness, when the risk of a dangerous metabolic crisis increases.