title: Effect of the Factor V Leiden mutation on the severity of meningococcal disease.
abstract: BACKGROUND
  One of the most serious complications of meningococcal disease is the syndrome of purpura fulminans, which is characterized by intravascular thrombosis and hemorrhagic infarction of skin, limbs and digits. The reasons why some patients with meningococcal disease develop purpura fulminans while others have minimal thrombotic and skin involvement despite having profound septic shock are not yet understood. The Factor V Leiden mutation (FV(L)) is associated with thrombotic events, and we hypothesized that children carrying FV(L) who develop meningococcal disease may be at increased risk of purpura fulminans.
  
  
  METHODS
  We determined the FV(L) genotype by PCR and restriction enzyme digestion (Mnl1) in 259 children with meningococcal disease and 80 healthy controls. In addition 79 parents of children with fatal meningococcal disease were studied.
  
  
  RESULTS
  There was no significant increase in the frequency of FV(L) in patients with meningococcal disease (10%) as compared with healthy controls (9%) or with the parents of children who died of meningococcal disease (12%). Although the mortality was not increased in patients heterozygous for FV(L), they had increased complications of purpura fulminans, as assessed by requirement for skin grafting, referral to plastic surgeon and/or amputation. Among survivors 5 of 24 (21%) of those heterozygous for FV(L) had complications, compared with 14 of 233 (7%) who were wild type [P < 0.03; relative risk, 3.1 (95% confidence intervals, 1.2 to 7.9)].
  
  
  CONCLUSIONS
  FV(L) exacerbates purpura fulminans in meningococcal disease but does not have a significant effect on mortality.
authors.affiliation: Department of Paediatrics, Imperial College School of Medicine at St. Mary's, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Kondaveeti
authors.forename: M L
authors.initials: ML
authors.lastname: Hibberd
authors.forename: R
authors.initials: R
authors.lastname: Booy
authors.forename: S
authors.initials: S
authors.lastname: Nadel
authors.forename: M
authors.initials: M
authors.lastname: Levin
mesh_terms: D002648:Child; D004211:Disseminated Intravascular Coagulation / Q000209:etiology / Q000235:genetics / Q000401:mortality; D005165:Factor V / Q000235:genetics*; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D011695:IgA Vasculitis / Q000209:etiology* / Q000235:genetics* / Q000401:mortality; D008589:Meningococcal Infections / Q000150:complications* / Q000235:genetics / Q000401:mortality; D009154:Mutation; D012307:Risk Factors
chemical_list: C095381:factor V Leiden; D005165:Factor V