[1] CHI, Dept Endocrinol, Temple St, Dublin, Ireland
[2] Univ Coll Dublin, Sch Med, Dublin, Ireland
[3] Univ Coll Cork, Dept Paediat & Child Hlth, Cork, Ireland
[4] Univ Penn, Perelman Sch Med, Philadelphia, PA 19104 USA
[5] Childrens Hosp Philadelphia, Div Endocrinol & Diabet, Philadelphia, PA 19104 USA
[6] CHI, Dept Clin Biochem, Temple St, Dublin, Ireland