title: Two novel mutations, Q1053H and C1060R, located in the D3 domain of von Willebrand factor, are responsible for decreased FVIII-binding capacity.
abstract: In type 2N von Willebrand disease (VWD), von Willebrand factor (VWF) is characterized by a markedly decreased affinity for Factor VIII (FVIII), and the mutations responsible are essentially located in the D' domain of VWF. We report the identification, in seven unrelated French families, of two novel type 2N VWD mutations, Q1053H and C1060R (Gln290His and Cys297Arg in mature VWF sequence), in exon 24 of the VWF gene. These missense mutations have been identified in the heterozygous, homozygous or hemizygous states. Using site-directed mutagenesis and transient expression in COS-7 cells, we showed that both mutations, although located in the D3 domain of VWF, outside the tryptic fragment containing the FVIII domain, dramatically decrease the binding of VWF to FVIII. In contrast, the R924Q substitution, which was identified in a patient who was heterozygous for C1060R, was shown to be a polymorphism.
authors.affiliation: Laboratoire Français du Fractionnement et des Biotechnologies, Centre Hospitalier de Bicêtre, Le Kremlin-Bicêtre, Hôpital A Trousseau, Paris, France. hilbert@ifb.fr
authors.forename: Lysiane
authors.initials: L
authors.lastname: Hilbert
authors.forename: Sylvie
authors.initials: S
authors.lastname: Jorieux
authors.forename: Valérie
authors.initials: V
authors.lastname: Proulle
authors.forename: Rémi
authors.initials: R
authors.lastname: Favier
authors.forename: Jenny
authors.initials: J
authors.lastname: Goudemand
authors.forename: Armelle
authors.initials: A
authors.lastname: Parquet
authors.forename: Dominique
authors.initials: D
authors.lastname: Meyer
authors.forename: Edith
authors.initials: E
authors.lastname: Fressinaud
authors.forename: Claudine
authors.initials: C
authors.lastname: Mazurier
mesh_terms: D000818:Animals; D019556:COS Cells; D004252:DNA Mutational Analysis / Q000379:methods; D005169:Factor VIII / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014842:von Willebrand Diseases / Q000235:genetics*; D014841:von Willebrand Factor / Q000235:genetics* / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D014841:von Willebrand Factor; D005169:Factor VIII