The deficiency group (n = 937, 70.3%) had significantly lower levels of education (50.60% vs. 56.25% above bachelor’s degree, p = 0.01), lower prevalence of PCOS (6.40% vs. 12.88%, p < 0.01), and lower serum levels of estradiol (42.10pg/ml vs. 45.35pg/ml, p = 0.01) but higher serum level of FSH (7.20mIU/ml vs. 6.95mIU/ml, p = 0.02) than the normal group (n = 396, 29.7%). The gene discussed is BRD2; the disease is hyperinsulinemic hypoglycemia, familial, 4.