Phenotypic study and molecular analysis of von Willebrand type 1 patients

ABSTRACT

Von willebrand disease [VWD] is the most common bleeding disorder caused by von willbrand factor [VWF] deficiency and autosomal dominance inheritance pattern. It is divided into three types, one and three [quantitative] and type 2 [qualitative]. Type one is known with mild bleeding symptoms in comparison with type 3. The aim of this study was to determine the mutations responsible for the type one VWD. DNA was extracted from affected members of the family with type 1 VWD and the von willebrand gene was amplified using 63 different PCR, Then PCR fragments were analyzed using CSGE gel electrophoresis, and the fragments with the extra bands were analyzed using DNA sequencing. The average of von willebrand antigen and VWF activity were found 35.18 and 31.4 unit/deciliter in 23 patients from 6 families, respectively. Mutations were found in 4 families from 6. Argenine 1205 to histidine in 2 families and two new mutations including glysine 19 to arginine in exon 2 and a nucleotide change 2821 guanine to adenine [G>A] in intron 21 splice site in two other families. No mutation was found in two other families.This study showed that different kind of mutations causing von willebrand disease in different families