Impact of Executive and Adaptive function on Functional Outcomes in Adults with Maple Syrup Urine Disease

PurposeSuccessful transition to adulthood requires intact executive and adaptive function. These neurocognitive domains, critical for independence, are frequently impaired in inherited metabolic disorders (IMD), though predictive clinical and biochemical factors are lacking. Standardized assessments linking neurocognitive status with functional outcomes are needed to improve prognostication and tailor support for affected emerging adults. MethodsMaple Syrup Urine Disease (MSUD), a relatively prevalent IMD, is primarily diagnosed in the first week of life through newborn screening. Despite early intervention, executive and adaptive dysfunction persist. We designed a remote, interactive battery of neurocognitive and functional assessments for adults ([≥]21 years) with MSUD to correlate neurocognition and long-term outcomes. ResultsAssessments completed by 28 adults with MSUD (23 diagnosed after symptom onset) show a wide range in educational attainment, employment, and residence. Executive function, and adaptive function were significantly impaired in adults with MSUD compared to controls. Executive and adaptive deficits correlated negatively with obtaining skills needed for adult-oriented healthcare or independent living. Clinical history did not predict functional outcomes, but neurocognitive assessments suggest the benefits of pre-symptomatic diagnosis. ConclusionIndependent adulthood is attainable for individuals with MSUD. Routine, targeted assessment of neurocognition may improve long-term functional outcomes in IMD.