Inclusion Criteria-Female Unaffected Relatives: 1) Aged at 18 yrs or above; 2) Regular menstrual cycles 21-35 days or history of regular menstrual cycles in the past if menopausal; 3) no clinical or biochemical evidence of hyperandrogenism; 4) normal TSH and prolactin <25 ng/mL; 5) on no hormonal or insulin sensitizing medication for at least 3 months.