[1] Univ Lyon 1, F-69365 Lyon, France
[2] IRCCS, Ist Giannina Gaslini, Div Pediat 2, Milan, Italy
[3] Univ Milan, Dipartimento Pediat, I-20122 Milan, Italy
[4] Univ Florence, Dipartimento Pediat, I-50121 Florence, Italy
[5] Univ Trieste, I-34127 Trieste, Italy
[6] Univ Padua, Dipartimento Pediat, I-35100 Padua, Italy