Similar to previous studies (11, 13), we observedserum LH Level to be significantly higher in somePCOS women with normal BMI, but Hendrikset al. (6) had found no correlation between LHconcentration and age or BMI in PCOS patients.Pagán et al. (14) found the LH pulse frequency iselevated in PCOS, but no influence of BMI on eithermarker of hypothalamic function was detected.In PCOS, the pituitary response to a weightbaseddose of GnRH is inversely related to BMI,these evidences suggested that in PCOS patientsthe effect of BMI on LH be interposed at a pituitaryand not a hypothalamic level. The gene discussed is GNRH1; the disease is polycystic ovary syndrome.