Type 2 von Willebrand disease (VWD) can present a diagnostic challenge. In an effort to address this, a research team recently characterized clinical and molecular patterns associated with type 2 VWD among patients in Iran. Findings were reported in the International Journal of Hematology.
Over a period of 13 years, 136 patients with type 2 VWD were evaluated for laboratory and clinical features. The researchers also performed molecular analyses of possible gene defects related to von Willebrand factor (VWF) in these patients. The patients had been seen at the Iranian Comprehensive Hemophilia Care Center in Tehran.
Clinical subtypes of type 2 VWD were variable in this population and occurred at rates of 30.9% for type 2A, 23.6% for type 2B, 27.9% for type 2M, and 17.6% for type 2N.
Epistaxis was reported in 49% of patients and was the most common clinical manifestation of type 2 VWD. Gum bleeding was reported in 30.2%, ecchymosis occurred in 23.2%, and easy bruising was reported in 22.5%. Some severe manifestations included menorrhagia in 16.3% of all patients, miscarriage in 2.3%, and umbilical cord bleeding in 0.8%.
The researchers reportedly detected 30 mutations occurring in the gene for VWF, 9 of which were newly observed. The most abundant modification was p.Arg1379Cys, while p.Val1316Met, p.Arg1597Trp, p.Arg1374Cys, p.Ser1506Leu, and p.Arg1308Cys were also common.
Some modifications associated with VWF appeared to be more common in patients with specific features. For instance, the p.Val1316Met variant occurred in approximately 10% of all patients in this study and among approximately 40% of those with type 2B VWD. This variant showed an association with thrombocytopenia and reportedly was present in 2 of the 3 patients in this study who experienced miscarriages.
“As in previous studies, this laboratory, clinical, and molecular study conducted for the first time on a large number of Iranian patients, revealed variable clinical and molecular characteristics in patients with type 2 [VWD],” the researchers concluded.
Rassoulzadegan M, Ala F, Jazebi M, et al. Molecular and clinical profile of type 2 von Willebrand disease in Iran: a thirteen-year experience. Int J Hematol. 2020;111(4):535-543.