MAPLE syrup urine disease (MSUD) is an inherited disorder of leucine, isoleucine, and valine metabolism. The basic defect is a failure in the degradation of these branched chain amino acids. In early infancy, the patient with MSUD may present with anorexia, vomiting, spasticity, and convulsions.1-5 Although death at an early age is frequent, we could not find a case of sudden and unexpected death in infancy due to this disease.
The frequency of MSUD is unknown, but it may be greater than the reported figures would indicate since failure to consider the diagnosis would result in a falsely low incidence. This possibility is to be expected in children dying suddenly before adequate diagnostic studies can be performed.
Recent reviews6-10 on the subject of sudden and unexpected death in infancy list various etiologic factors but none specifically mentions MSUD. Two of the reviews6,9 list a metabolic crisis secondary
Hallock J, Morrow G, Karp LA, Barness LA. Postmortem Diagnosis of Metabolic DisordersThe Finding of Maple Syrup Urine Disease in a Case of Sudden and Unexpected Death in Infancy. Am J Dis Child. 1969;118(4):649–651. doi:10.1001/archpedi.1969.02100040651022
Customize your JAMA Network experience by selecting one or more topics from the list below.