Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_238124_1 ( prothrombin_time VARCHAR, condition VARCHAR )

### Question ###
What is the prothrombin time of von willebrand disease?

### Accurate SQL ###

SELECT COUNT(prothrombin_time) FROM table_238124_1 WHERE condition = "Von Willebrand disease"