As of October 2015, ICD-9 codes are no longer used for medical coding. Instead, use the following five equivalent ICD-10-CM codes, which are an approximate match to ICD-9 code 289.81.
D68.52 is a billable ICD code used to specify a diagnosis of prothrombin gene mutation
ICD-10 Code D68.51, Activated protein C resistance.
D68.59 is a billable ICD code used to specify a diagnosis of other primary thrombophilia.
(To the best of my knowledge)