Maple Syrup Urine Disease Type Ib: 3-year Outcome of a Case of Early Liver Transplantation in Russia

Background: Maple Syrup Urine Disease (MSUD) is an autosomal recessive inherited disorder. Despite advances in medical nutrition therapies, many patients with neurological disorders and sudden death have been described. Successful liver transplantation (LT) experiences have been reported in severe cases of MSUD. Herein, we report the 3-year outcome of an MSUD patient who underwent LT at the age of 9 months.

Case Study/Methods: A girl with pathogenic BCKDHB variants: NM_000056:c.608CT (p.Arg170Cys) and NM_000056: c.662CA (p.Ala221Asp) was diagnosed on her 7th day of life with high-risk screening [MS/MS leucine level 4179.38 mkM/l (30-370), valine - 685.68 mkM/l (25-320)] because of symptoms of lethargy. Emergency treatment with a low-protein diet and thiamine was immediately started. After her condition stabilised, she continued the low-protein diet with a special meal formula. Despite treatment, she did not achieve the target values of plasma leucine levels [leucine level in 5 m.o. 709.16 mkM/l (30-370)] within 5 months. On March 2020 (9 m.o.), she underwent a related liver transplant from her mother. Since the liver transplantation, despite ongoing concomitant therapy, plasma levels of leucine and valine have remained within normal limits. The child is now 3 years old, growing and developing according to age, without requiring protein restrictions or a special meal formula. No metabolic crisis has been recorded during the 3 years of follow-up.

Conclusion/Discussion: Many descriptions of LT in MSUD exist, most of which report on LT in severe cases of the disease in patients older than 1 year. We report the successful experience of early LT with excellent metabolic and somatic states after LT, without the need for a special diet.