Complete factor H deficiency-associated atypical hemolytic uremic syndrome in a neonate

Pediatr Nephrol. 2007 Jun;22(6):874-80. doi: 10.1007/s00467-007-0438-x. Epub 2007 Feb 13.

Abstract

Recent advances have shown that atypical hemolytic uremic syndrome (aHUS) is a disease of complement dysregulation. Almost 50% of cases are associated with mutations in the three complement regulatory genes, factor H (HF1), membrane co-factor protein (MCP) and factor I (IF). The corresponding gene products act in concert and affect the same enzyme, alternative pathway convertase C3bBb, which initiates the alternative pathway and amplification of the complement system. Factor H (FH) deficiency-associated aHUS usually occurs in infants to middle-aged adults and only rarely in neonates. Moreover, the vast majority of patients are heterozygous for the HF1 gene mutations. We report on a case of neonatal-onset aHUS associated with complete FH deficiency due to novel compound heterozygous mutations in the HF1 gene. A 22-day-old baby girl developed acute renal failure and a remarkably low serum complement C3 level, which was rapidly followed by the development of micro-angiopathic hemolytic anemia. Western blot analysis revealed nearly zero plasma FH levels, and an HF1 gene study showed compound heterozygous mutations, C1077W/Q1139X. Renal pathology findings were compatible with glomerular involvement in HUS. The baby recovered completely after the repetitive infusion of fresh frozen plasma. During follow-up (until she was 20 months old) after the initial plasma therapy, the disease recurred three times; twice after the tapering off of plasma therapy, and once during a weekly plasma infusion. All recurrence episodes were preceded by an upper respiratory tract infection, and were successfully managed by restarting or increasing the frequency of plasma therapy.

Publication types

  • Case Reports

MeSH terms

  • Biomarkers / metabolism
  • Biopsy
  • Codon, Nonsense
  • Complement Factor H / deficiency
  • Complement Factor H / genetics
  • DNA Mutational Analysis
  • Female
  • Hemolytic-Uremic Syndrome / blood*
  • Hemolytic-Uremic Syndrome / genetics
  • Hemolytic-Uremic Syndrome / therapy
  • Humans
  • Infant, Newborn
  • Kidney Glomerulus / metabolism
  • Kidney Glomerulus / pathology
  • Kidney Glomerulus / ultrastructure
  • Mutation, Missense
  • Plasma Exchange / methods
  • Point Mutation*
  • Renal Insufficiency / blood
  • Renal Insufficiency / genetics
  • Renal Insufficiency / therapy
  • Treatment Outcome

Substances

  • Biomarkers
  • CFH protein, human
  • Codon, Nonsense
  • Complement Factor H