What is maple syrup urine disease (MSUD)?
There is a classic form of MSUD and several less common forms. Each form varies in its severity and characteristic features. However, all subtypes of the disorder can be caused by mutations in any of the 6 genes used to build the BCKD protein complex. A baby who has the disorder may appear normal at birth. But within three to four days, the symptoms appear. These may include: loss of appetite, fussiness, and sweet-smelling urine. The elevated levels of amino acids in the urine generate the smell, which is reminiscent of maple syrup. This is how MSUD got its name. If left untreated, the condition usually worsens. The baby will have seizures, go into a coma, and die within the first few months of life.
