F5 and androgen insensitivity syndrome: In turn, the study by Pezzini et al. [48], which was performed in a large cohort of over 500 patients with AIS younger than 45 years, three of the commonly analyzed polymorphisms (the 20210A variant of the prothrombin gene, the 1691A variant of the FV gene, and the TT677 genotype of the MTHFR gene) were assessed in relation to the recurrence of ischemic events.