Thromb Haemost 1992; 67(06): 618-622
DOI: 10.1055/s-0038-1648511
Original Articles
Schattauer GmbH Stuttgart

Characterization of Three Mutations Causing von Willebrand Disease Type IIA in Five Unrelated Families

Aida Inbal
1   The Hematology Unit, Beilinson Medical Center, St.Thomas’Hospital, London, U. K.
3   Sackler School of Medicine, Israel, St.Thomas’Hospital, London, U. K.
,
Uri Seligsohn
2   Institute of Hematology, Tel Aviv Medical Center, Ichilov Hospital, St.Thomas’Hospital, London, U. K.
3   Sackler School of Medicine, Israel, St.Thomas’Hospital, London, U. K.
,
Nurit Kornbrot
1   The Hematology Unit, Beilinson Medical Center, St.Thomas’Hospital, London, U. K.
3   Sackler School of Medicine, Israel, St.Thomas’Hospital, London, U. K.
,
Benjamin Brenner
4   Rambam Medical Center, Israel, St.Thomas’Hospital, London, U. K.
,
Paul Harrison
5   Coagulation Research Unit, The Rayne Institute, St.Thomas’ Hospital, London, U. K.
,
Anna Randi
7   Department of Medicine and of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, U.S.A.
,
Ian Rabinowitz
6   Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO, U. S. A.
7   Department of Medicine and of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, U.S.A.
,
J Evan Sadler
6   Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO, U. S. A.
7   Department of Medicine and of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, U.S.A.
› Author Affiliations
Further Information

Publication History

Received 28 October 1991

Accepted after revision 10 January 1992

Publication Date:
03 July 2018 (online)

Zoom Image

Summary

Von Willebrand disease (vWD) type IIA is characterized by decreased ristocetin-induced platelet aggregation, and by the absence from plasma of high molecular weight multimers of von Willebrand factor (vWF). Most mutations causing vWD type IIA are clustered within the A2 domain of the mature vWF subunit that is encoded by exon 28. Using the polymerase chain reaction (PCR), the entire exon 28 from patients with vWD type IIA and normal controls was amplified and sequenced. Three missense mutations were detected that result in the amino acid substitutions Arg(834)→Trp, Gly(742)→Glu, and Ser(743)→Leu. The first mutation occurred independently in three unrelated families; each of the latter mutations was found in one family. By restriction endonuclease analysis and allele-specific oligonucleotide (ASO) hybridization the mutations were confirmed in affected family members and excluded in unaffected members and 50 normal controls. The apparently high frequency of identical independent mutations among patients with vWD type IIA suggests that a precise diagnosis may be possible in a majority of patients using relatively simple recombinant DNA screening assays.