[The phenotypic and genotypic diagnosis of three Chinese patients with von Willebrand disease].

OBJECTIVE

To analyze the phenotype and genotype of three patients with von Willebrand disease (vWD), and to explore its molecular pathogenesis.

METHODS

Bleeding time (BT), APTT, ristocetin induced platelet aggregation (RIPA), von Willebrand factor (vWF):ristocetin cofactor (Rco) (vWF:Rco), vWF antigen (vWF:Ag), vWF activity (vWF:A) test, vWF collagen binding assay (vWF:CB) and multimer analysis were detected for phenotype diagnosis. The dynamic process of blood coagulation was evaluated by using the thrombelastography. Genomic DNA was extracted from the peripheral blood. The vWF gene mutation was detected by sequencing.

RESULTS

APTT, BT were prolonged in the three probands. Plasma vWF:Rco, vWF:Ag, vWF:A and vWF:CB were decreased in different degrees. RIPA was reduced in probands B and C. vWF multimer analysis found the lost of the large molecular weight multimers in proband B, while basically normal in probands A and C. The dynamic process of blood coagulation of proband C presented obvious hypocoagulability by using the thrombelastography. Heterozygous missense mutation g.106782G > T resulting in Cys1130Phe in exon 26, g.110988G > A resulting in Gly1579Arg in exon 28 and g.110373C > T resulting in Arg1374Cys in exon 28 were found in the probands A, B and C, respectively.

CONCLUSION

Three probands were diagnosed as type 1, type 2A or type 2M vWD by phenotype detection. Heterozygous missense mutation Cys1130Phe, Gly1579Arg and Arg1374Cys induced vWD of three probands, respectively.