Domino liver transplantation in maple syrup urine disease: a case report and review of the literature.

BACKGROUND: Improved outcomes have expanded the indications for liver transplantation, thus aggravating the already limited supply of donor organs. Domino liver transplantation (DLT) has been one strategy to augment the supply of donor organs in cases of inborn errors of metabolism. One such disease is maple syrup urine disease (MSUD), an inherited disorder of branched-chain amino acid (BCAA) metabolism. METHODS: We report on the transplantation of a deceased donor liver into a patient with MSUD, and the sequential transplantation of the explanted liver into a patient with hemophilia A, HIV, hepatitis C, and a low priority on the transplant waiting list. RESULTS: At 30 months, the MSUD recipient has had significant correction of BCAA metabolism on a protein-unrestricted diet and no progression of neuropsychiatric symptoms. The DLT recipient has been cured of hemophilia and has normal BCAA homeostasis. This case provides further evidence that elective orthotopic liver transplantation for MSUD attenuates the disease with restoration of BCAA metabolism, and that DLT in this setting can achieve excellent results in ESLD patients. CONCLUSION: It is possible that domino grafts from patients with MSUD could be used in more conventional recipients, but additional studies and longer-term outcomes are needed to determine the validity of DLT in MSUD.