title: Effect of prothrombotic mutations on factor consumption in children with hemophilia.
abstract: BACKGROUND
  In hemophilia A, factor activity usually correlates with clinical severity; however, there are patients with severe hemophilia who have bleeding less than expected.
  
  
  OBJECTIVE
  The aim of this study is to evaluate the impact of prothrombotic mutations on annual factor consumption in children with hemophilia.
  
  
  METHODS
  Factor V Leiden (FVL) G1691A, Prothrombin (PT) G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T and A128C mutations were evaluated in children with moderate-severe hemophilia A (n = 51) and controls (n = 25).
  
  
  RESULTS
  None of the cases and controls carried the FVL and PT G20210A in homozygous state. There was no difference in factor consumption between carriers of FVL, PT mutations, and noncarriers. Patients who were homozygous for MTHFR C677T were found to have increased factor consumption compared to noncarriers, and this was a negative association. No decrease in factor consumption was noted in patients with hemophilia having MTHFR A1298C mutation.
  
  
  CONCLUSIONS
  We could not demonstrate a significant decrease in factor concentrate consumption in children with hemophilia having prothrombotic mutations.
authors.affiliation: Pediatric Intensive Care Unit, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey.
authors.forename: Hamit
authors.initials: H
authors.lastname: Tüten
authors.forename: Halit
authors.initials: H
authors.lastname: Çam
authors.forename: Nihal
authors.initials: N
authors.lastname: Özdemir
authors.forename: Fikret
authors.initials: F
authors.lastname: Bezgal
authors.forename: Nur
authors.initials: N
authors.lastname: Buyru
authors.forename: Bülent
authors.initials: B
authors.lastname: Zülfikar
authors.forename: Tiraje
authors.initials: T
authors.lastname: Celkan
mesh_terms: D016022:Case-Control Studies; D002648:Child; D005165:Factor V / Q000235:genetics; D006467:Hemophilia A / Q000097:blood / Q000235:genetics*; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D009154:Mutation; D011516:Prothrombin / Q000235:genetics*; D012189:Retrospective Studies
chemical_list: C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)