[1] Univ Roma Tor Vergata, Dipartimento Med Interna, Mol Med Lab, I-00173 Rome, Italy
[2] Univ Roma La Sapienza, Div Endocrinol, Rome, Italy
[3] Univ Cattolica Sacro Cuore, Inst Endocrinol, I-00168 Rome, Italy
[4] NICHHD, Dev Endocrinol Branch, NIH, Bethesda, MD 20892 USA