The present invention relates to a method for assessing whether a subject has Polycystic Ovarian Syndrome (PCOS) or is at risk of developing PCOS, to a method of selecting a patient for therapy of PCOS, to a method for monitoring PCOS progression or for monitoring response to treatment and to a computer-implemented method for assessing a subject with suspected PCOS, by determining the amount or concentration of Leukotriene A4 Hydrolase (LTA4H) in a sample of the subject.

The present invention relates to a method for diagnosing Polycystic Ovarian Syndrome (PCOS) in a subject, said method comprising the steps of a) determining the amount or concentration of total LTA4H in sample from the subject, b) determining the amount or concentration of METRNL in a sample from the subject, c) calculating a score of the amounts or concentration determined in steps a) and b), d) comparing the calculated score with a reference score, and e) diagnosing PCOS in a subject.