Clinical Profiles, Genetic Variants, and Neurodevelopmental Outcomes Following Liver Transplantation in Maple Syrup Urine Disease: A Study From Palestine

Maple syrup urine disease (MSUD) is a rare, autosomal recessive metabolic disorder resulting from a deficiency of the branched-chain α-ketoacid dehydrogenase complex. This leads to the accumulation of branched-chain amino acids and their corresponding ketoacids, causing acute metabolic crises and progressive neurological damage if untreated. The impact of founder variants, high consanguinity, and limited access to metabolic care pose challenges in medically underserved populations, such as in Palestine. We conducted a retrospective analysis of 11 patients from eight Palestinian families referred to the main Metabolic Unit in the West Bank. Clinical data, biochemical profiles, and molecular findings were reviewed to characterize the presentation and outcomes of MSUD. Management strategies, including dietary intervention and liver transplantation, were also evaluated. Acute metabolic crises were the initial presentation in 91% of cases, typically within the first days of life. Diagnostic delay averaged 47 days in families without prior MSUD history, compared to 2.3 days in those with affected siblings. Founder pathogenic variants were identified in multiple unrelated families, reflecting genetic homogeneity due to community structure; novel variants were also detected. Timely diagnosis facilitated early referral and improved outcomes. Patients who underwent liver transplantation, especially when performed early, exhibited favorable developmental trajectories, increased leucine tolerance, and fewer hospitalizations. One participant diagnosed prenatally remained free of metabolic crises until transplantation at age six, with excellent neurocognitive outcomes. This study highlights the importance of integrating prenatal screening and early diagnosis, timely dietary intervention, and liver transplantation to improve MSUD outcomes in resource-limited settings.