Phenotype and genotype analysis of a Chinese pedigree with 2N type von Willebrand disease

doi:10.16150/j.1671-2870.2018.02.006

Abstract

Abstract: Objective: To analyze the phenotype and genotype of one Chinese pedigrees with von Willebrand disease and to investigate the molecular pathogenesis of the disease. Methods: Indices including bleeding time(BT), activated partial thromboplastin time (APTT), ristocetin-induced platelet aggregation(RIPA), von Willebarand factor-ristocetin cofactor (vWF:Rco), von Willebrand factor antigen (vWF:Ag), von Willebrand factor activity (vWF:Act), von Willebrand factor collagen binding assay (vWF:CB) and von Willebrand factor FⅧ binding assay (vWF: FⅧ:B) were detected for phenotype diagnosis. Peripheral blood DNA was extracted, and all of the exons and exon-intron boundaries of the VWF and F8 gene were amplified by polymerase chain reaction (PCR) and analyzed with direct sequencing. Results: The results revealed that APTT and BT of proband were prolonged while plasma RIPA, vWF:Rco, vWF:Ag, vWF:Act and vWF:CB were normal. FⅧ:C and vWF: FⅧ:B were significantly decreased. Homozygous missense mutation c.2446C>T (p.Arg816Trp) in exon 19 of VWF gene was identified in proband and heterozygous mutation was identified in his son. No mutation in F8 gene was found in proband. Conclusions: Homozygous missense mutation c.2446C>T (p.Arg816Trp) in exon 19 of VWF gene is the cause of 2N type von Willebrand disease in the proband.

Key words: von Willebrand disease, von Willebrand factor, Gene mutation

CLC Number:

R554⁺.1

JIN Peipei, LIANG Qian, DAI Jing, DING Qiulan, SUN Shunchang, WANG Xuefeng. Phenotype and genotype analysis of a Chinese pedigree with 2N type von Willebrand disease[J]. Journal of Diagnostics Concepts & Practice, 2018, 17(02): 151-154.

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