MNGIE Syndrome: Liver Cirrhosis Should Be Ruled Out Prior to Bone Marrow Transplantation.

Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is an autosomal recessive mitochondriopathy caused by loss-of-function mutations in the thymidine phosphorylase gene. The disease leads to premature death and is characterized by gastrointestinal dysmotility and cachexia, external ophthalmoplegia, a sensorimotor neuropathy, and leukoencephalopathy. Bone marrow transplantation (BMT) is the only potentially curative treatment that can achieve a sustained biochemical correction of the metabolic imbalances.We report a 23-year-old male homozygous for the c.866A > C, p.Glu289Ala mutation of the TYMP gene, who presented with fatty liver and cachexia. Laboratory examinations were unremarkable except for increased transaminase activities. Grade II fibrosis and steatosis was found in an initial and a follow-up liver biopsy 4 years later. Myeloablative conditioning and BMT was performed 10 years after initial presentation due to the progressive weight loss and polyneuropathy. Pre-transplant liver staging was normal except for an elevated transient elastography of 31.6 kPa. Severe ascites developed after transplantation and liver function deteriorated progressively to liver failure. Despite engraftment on day +15, the patient died on day +18 from liver failure. Autopsy revealed micronodular liver cirrhosis, and postmortem diagnosis of acute-on-chronic liver failure was done.This case illustrates the difficulties and importance of diagnosing liver cirrhosis in MNGIE. Before BMT, patients must be carefully evaluated by transient elastography, liver biopsy, or assessment of hepatic venous pressure gradient. In patients with liver cirrhosis, further studies should evaluate if liver transplantation may be an alternative to BMT. Considerable amounts of thymidine phosphorylase are expressed in liver tissue which may prevent accumulation of toxic metabolites.