[1] Univ Autonoma Madrid, Hosp Infantil Nino Jesus, Dept Pediat Endocrinol & Res, E-28009 Madrid, Spain
[2] Univ Autonoma Madrid, Hosp Infantil Nino Jesus, Dept Biochem, E-28009 Madrid, Spain
[3] Univ Complutense, Hosp Infantil 12 Octubre, Pediat Intens Care Unit, Madrid, Spain
[4] Univ Autonoma Madrid, Hosp Infantil La Paz, Dept Neonatol, Madrid, Spain