[1] Univ Naples 2, Dipartimento Biochim Biofis & Patol Gen, Via Luigi De Crecchio 7, I-80138 Naples, Italy
[2] Telethon Inst Genet & Med TIGEM, Pozzuoli, Italy
[3] Univ Helsinki, Folkhalsan Inst Genet, Helsinki, Finland
[4] Univ Helsinki, Dept Med Genet, Haartman Inst, Helsinki, Finland