title: von Willebrand disease with G4022A mutation (vWd Sungnam): a case report.
abstract: A 10-year-old male patient affected by type 2 von Willebrand disease (vWD) and his family members were investigated by hemostatic and molecular genetic studies. The propositus, who experienced frequent bleeding episodes, was characterized by a normal level of von Willebrand factor (vWF) antigen (54%), reduced vWF ristocetin cofactor activity (5%), decreased factor VIII clotting activity (25%) and absent high molecular weight multimers in the plasma. An exon 28 fragment coding for the A1 and A2 domains was amplified by polymerase chain reaction and sequenced. We found a heterozygous mutation (G4022A), producing an additional PstI restriction site, which resulted in the substitution of Arg578Gln. Family studies, including the parents and a brother, were negative for this mutation and vWF abnormalities were not observed. We confirmed that G to A mutation in the region of the platelet glycoprotein Ib binding domain of vWF causes the qualitative type 2 defect in von Willebrand disease.
authors: Department of Clinical Pathology, Yonsei University College of Medicine, Seoul, Korea. kssong@yumc.yonsei.ac.kr
authors: K S
authors: KS
authors: Song
authors: S H
authors: SH
authors: Kang
authors: M S
authors: MS
authors: Kang
authors: Y S
authors: YS
authors: Park
authors: J R
authors: JR
authors: Choi
authors: H K
authors: HK
authors: Kim
authors: Q
authors: Q
authors: Park
mesh_terms: D000409:Alanine / Q000235:genetics*; D002648:Child; D005998:Glycine / Q000235:genetics*; D006801:Humans; D008297:Male; D017354:Point Mutation; D014842:von Willebrand Diseases / Q000235:genetics*; D014841:von Willebrand Factor / Q000235:genetics*
chemical_list: D014841:von Willebrand Factor; D000409:Alanine; D005998:Glycine