title: [Incomplete hemolytic uremic syndrome associated with partial factor H deficiency].
abstract: Hemolytic uremic syndrome (HUS) consists of the association of hemolytic anemia, thrombocytopenia and renal failure. Most cases are related to toxins (verotoxins) produced by Escherichia coli 0157:H7 and generally have good renal prognosis. Atypical forms can occur, with a less favorable prognosis, and can be due to mutations in the gene codifying factor H, a protein that regulates activation of the alternative complement pathway, among other causes. Factor H deficiency produces continuous complement activation, causing injury to capillary endothelial cells. We report a case of incomplete (absence of thrombocytopenia and uremia), atypical HUS in which hypocomplementemia secondary to partial factor H deficiency was detected, with favorable outcome. Prior to symptom onset, the patient had a Campylobacter infection, precipitating the symptoms. Genetic analysis showed a heterozygous mutation (C846T) located in the SCR4 domain, generating an amino acid change in the factor H molecule (Pro240Leu). This mutation may have been the cause of the partial factor H deficiency and the patient's symptoms on admission.
authors.affiliation: Unidad de Lactantes, Hospital Donostia, San Sebastián, España. iolaciregui@chdo.osakidetza.net
authors.forename: I
authors.initials: I
authors.lastname: Olaciregui Echenique
authors.forename: R
authors.initials: R
authors.lastname: Areses Trapote
authors.forename: M
authors.initials: M
authors.lastname: Ubetagoyena Arrieta
authors.forename: I
authors.initials: I
authors.lastname: Sota Busselo
authors.forename: C
authors.initials: C
authors.lastname: García Pardos
authors.forename: P
authors.initials: P
authors.lastname: Echaniz Aizpuru
mesh_terms: D017242:Complement Factor H / Q000172:deficiency* / Q000235:genetics; D006463:Hemolytic-Uremic Syndrome / Q000209:etiology*; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation
chemical_list: D017242:Complement Factor H