title: [Type 2N von Willebrand disease (Normandy)].
abstract: BACKGROUND
  the results of the laboratory test for 2N von Willebrand disease (2N vWD) are indistinguishable from those of light or moderate haemophilia A, until the technique that evaluates the operation of the vWF: FVIII binding is performed.
  
  
  OBJECTIVE
  to determine the prevalence of type 2N vWD in patients diagnosed with light or moderate haemophilia A and type 1 vWD.
  
  
  METHODS
  twelve healthy donors and twenty-five patients diagnosed with haemophilia A (a carrier) and five suspected of type 1 vWD were included in the study. The common tests of haemostasis for this condition plus the technique of the relationship of the vWF: FVIII recombinant (F VIIIr) binding was performed.
  
  
  RESULTS
  the laboratory results of the 30 patients were concordant with the previous diagnosis. However, three with a previous diagnosis of haemophilia A demonstrated a rate of relationship of the vWF: F VIIIr binding lower than the reference interval obtained from the healthy donors, which means it corresponds to 2N vWD.
  
  
  CONCLUSIONS
  the screening method of 2N vWD employed in this study allowed to identify for first time in Mexico, the first cases of this variant with a prevalence of 10%. In our country, this method will allow to establishing accurate diagnosis of 2N vWD and to providing specific treatments.
authors.affiliation: Laboratorio Central, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social. ale_morav@yahoo.com.mx
authors.forename: Alejandro
authors.initials: A
authors.lastname: Morales-De la Vega
authors.forename: Elba
authors.initials: E
authors.lastname: Reyes-Maldonado
authors.forename: Carlos
authors.initials: C
authors.lastname: Martínez-Murillo
authors.forename: Sandra
authors.initials: S
authors.lastname: Quintana-González
mesh_terms: D000293:Adolescent; D000328:Adult; D001782:Blood Donors; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006467:Hemophilia A / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D009154:Mutation / Q000235:genetics; D015995:Prevalence; D014842:von Willebrand Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D014841:von Willebrand Factor / Q000235:genetics
chemical_list: D014841:von Willebrand Factor