A study of von Willebrand's disease in Jordan.

This work reports on the results of a 9-year study of von Willebrand's disease and its subtypes in Jordan, a country with a predominantly Arab population. There were a total of 65 patients in 32 families. Detailed study of 61 patients including von Willebrand factor multimers was done for the purpose of subtyping them. Type I and variants were seen in 36 patients (59%). Type II A and variants with decreased ristocetin response accounted for seven patients (11.5%), while 11 (18%) were of type II B. The severe type (type III) accounted for seven patients (11.5%). Von Willebrand's disease was the second most commonly seen inherited bleeding disorder after hemophilia A. It is concluded that although the observed frequency of von Willebrand's disease in this study in Jordan is lower than that in Europe and the USA, the true prevalence cannot be ascertained since many of the mild cases presumably were missed because of referral patterns. Type I and its variants was the most common type found, but the observed frequency of types II B and III was more than that reported in Europeans and Americans.