Rare VPS33B gene mutation combined with GP1BA mutation causes severe decrease in plasma VWF levels: a case report and literature review
10.3760/cma.j.cn121090-20231216-00317
- VernacularTitle:VPS33B与GP1BA基因双重杂合变异致血浆VWF水平严重降低：1例报告及文献复习
- Author:
Siqian MA
1
;
Xia BAI
;
Lijuan CAO
;
Zhenni MA
;
Zixuan DING
;
Ziqian YU
;
Miao JIANG
Author Information
1. 苏州大学附属独墅湖医院血液科，苏州 215028
- From:
Chinese Journal of Hematology
2024;45(6):602-605
- CountryChina
- Language:Chinese
-
Abstract:
A 28-year-old woman was found to have coagulation factor Ⅷ activity (FⅧ∶C) <1% and von Willebrand factor antigen (VWF∶Ag) <1% during routine prenatal examinations. No pathogenic variation was found in the exon region of the VWF gene using next-generation sequencing. The clinical presentation of this patient does not match the clinical characteristics of type Ⅲ hemophilia [von Willebrand disease (VWD) ]; therefore, third-generation sequencing technology was used to perform whole-genome sequencing on the patient and her family members. Multiple members of the patient’s paternal family carried a heterozygous variant of VPS33B, c.869G>C. The family members carrying this variant all had varying degrees of reduced VWF levels (39% -56% ). Moreover, the proband was detected with the heterozygous variant c.1474dupA in GP1BA. The ACMG and Clinvar databases determined that this variation was associated with platelet-type pseudo VWD. The decrease in VWF levels caused by heterozygous variations in VPS33B in families is the first international report, and no previous studies have reported cases of severe decrease in plasma VWF levels caused by double heterozygous variations in VPS33B and GP1BA.
