Liver transplantation recovers hepatic N-glycosylation with persistent IgG glycosylation abnormalities: Three-year follow-up in a patient with phosphomannomutase-2-congenital disorder of glycosylation

Mol Genet Metab. 2023 Apr;138(4):107559. doi: 10.1016/j.ymgme.2023.107559. Epub 2023 Mar 17.


Phosphomannomutase-2-congenital disorder of glycosylation (PMM2-CDG) is the most common CDG and presents with highly variable features ranging from isolated neurologic involvement to severe multi-organ dysfunction. Liver abnormalities occur in in almost all patients and frequently include hepatomegaly and elevated aminotransferases, although only a minority of patients develop progressive hepatic fibrosis and liver failure. No curative therapies are currently available for PMM2-CDG, although investigation into several novel therapies is ongoing. We report the first successful liver transplantation in a 4-year-old patient with PMM2-CDG. Over a 3-year follow-up period, she demonstrated improved growth and neurocognitive development and complete normalization of liver enzymes, coagulation parameters, and carbohydrate-deficient transferrin profile, but persistently abnormal IgG glycosylation and recurrent upper airway infections that did not require hospitalization. Liver transplant should be considered as a treatment option for PMM2-CDG patients with end-stage liver disease, however these patients may be at increased risk for recurrent bacterial infections post-transplant.

Keywords: CDG; Glycosylation; Immunoglobulin; Infection; Liver transplantation; PMM2-CDG; Phosphomannomutase.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural

MeSH terms

  • Child, Preschool
  • Congenital Disorders of Glycosylation* / complications
  • Congenital Disorders of Glycosylation* / genetics
  • Female
  • Follow-Up Studies
  • Glycosylation
  • Humans
  • Immunoglobulin G
  • Liver / metabolism
  • Liver Transplantation*
  • Phosphotransferases (Phosphomutases)* / genetics


  • phosphomannomutase
  • Phosphotransferases (Phosphomutases)
  • Immunoglobulin G

Supplementary concepts

  • Congenital disorder of glycosylation type 1A