PMM2-CDG and the Role of Liver Transplantation as a Long-Term Solution: A Case Report

Phosphomannomutase-2 congenital disorder of glycosylation (PMM2-CDG) is the most common congenital disorder of glycosylation, affecting protein glycosylation across multiple organ systems. Hepatic involvement may range from isolated elevations in liver transaminases to end-stage liver disease. Reported outcomes of liver transplantation as a treatment modality are sparse.

We describe one of the first reported cases of liver transplantation in a child with PMM2-CDG and interim post-transplant outcomes. This patient was diagnosed at 4 months of age after presenting with failure to thrive, lipodystrophy, hypotonia, developmental delay, elevated transaminases, hypoalbuminemia, and coagulopathy. He developed cirrhosis and portal hypertension as well as sequelae of poor protein glycosylation. All these included coagulopathy, protein-losing enteropathy, and refractory ascites requiring serial intravenous fresh frozen plasma and furosemide. He ultimately underwent a liver transplant, after which his ascites resolved. Post-transplant, he developed new-onset recurrent pericardial effusions, suspected to be from a viral etiology versus extrahepatic manifestations of PMM2-CDG, and elevated transaminases following transplantation.

Liver transplantation may offer clinical benefit in PMM2-CDG with severe hepatic involvement, including resolution of ascites and improved quality of life, due to its potential to restore liver glycosylation function. However, this is only a partial correction as persistent extrahepatic manifestations underscore the need for further research into transplant outcomes and systemic disease progression in CDG.