Increased mortality and disability in a cohort of Mexican children with maple syrup urine disease

INTRODUCTION: Maple syrup urine disease (MSUD) is a genetic disorder that produces ketoacidosis crises and neurological complications often leading to death. The age of diagnosis and treatment determine a child's adequate and healthy outcome. OBJECTIVE: Describe the characteristics of a pediatric Mexican cohort with MSUD. MATERIAL AND METHODS: Retrospective analysis of MSUD cases seen at our Metabolic Unit between 1991- 2006. RESULTS: We studied 36 patients; three were initially detected through neonatal screening, one of them done in Mexico and two in the United States. The latter were given timely treatment and developed normally, both intellectually and physically. The patient detected in Mexico was not given adequate treatment and died at 3 months of age. The remaining 33 patients were diagnosed between 2-24 months using standard biochemical tests performed after symptoms became noticeable. All symptomatic patients had high levels of branched-chain amino acids. Hypotonia, refusal to eat and seizures were the most frequent symptoms. The cohort's mortality was 50% (18/36), while 81.2% (13/18) of survivors displayed cognitive impairment. DISCUSSION: Mexico needs a comprehensive treatment protocol for the care of MSUD patients including newborn screening, early treatment, follow-up and genetic counseling.