Type 2N von Willebrand disease (vWD) can be confused with
hemophilia A due to decreased
factor VIII levels and a
bleeding tendency, and differential diagnosis is of importance for providing the optimal treatment and genetic counseling. For the accurate diagnosis of type 2N vWD,
von Willebrand Factor (vWF) function tests, multimer assay and gene mutation analysis are needed. The patient was a 38-yr-old Nepalese woman with a history of
bleeding manifestations from childhood, such as
hemarthrosis, intramuscular
hematoma, and
menorrhagia. Family history revealed that her mother and elder brothers also had
bleeding manifestations from childhood. When she had a
laparotomy in 1991, she was diagnosed as
hemophilia A with
factor VIII level of 3.6% and was transfused with whole blood,
factor VIII and cryoprecipitates. In June 2007, she was admitted to our hospital for further evaluation of
bleeding tendency. Blood tests revealed normal CBC; bleeding time, 2 min; PT, 14.9 sec (11-14 sec); aPTT, 51.2 sec (24-38 sec); and
factor VIII, 4.9% (50-150%). The prolonged aPTT was corrected by 1:1 mixing test to the levels of 106% and 84%, respectively, before and after 2 hr-incubation at 37degrees C. No abnormalities were found in the vWF
antigen level (71.3%),
ristocetin cofactor assay (130.4%), and multimer assay. Direct
DNA sequencing of the VWF gene revealed homozygous missense mutation located in exon 19, c.2446C>T (p.Arg816Trp), confirming the diagnosis of type 2N vWD.