For the patients with an abnormal activated partial prothrom bin time, how many of them have a mild thrombosis?
abnormal activated partial prothrom bin time refers to APTT > 45; mild thrombosis refers to Thrombosis = 3; Only count ones without repetitive.
SELECT COUNT(DISTINCT T1.ID) FROM Patient AS T1 INNER JOIN Laboratory AS T2 ON T1.ID = T2.ID INNER JOIN Examination AS T3 ON T3.ID = T2.ID WHERE T3.Thrombosis = 3 AND T2.APTT > 45