Delabaere et al. [29] and Langroudi et al. [30] reported spontaneous OHSS during pregnancy in a context of moderate hypothyroidism and supposed that the etiology of spontaneous OHSS should seek hypersecretion of glycoprotein hormones (hCG, TSH, FSH and LH) and/or mutation of FSH and LH receptors; thus raising a possibility of endocrinal basis for development of OHSS. The gene discussed is BRD2; the disease is hypothyroidism.