[1] Childrens Hosp Westmead, Sydney, NSW, Australia
[2] Univ Alberta, Edmonton, AB, Canada
[3] Peking Univ, Natl Ctr Maternal & Infant Hlth, Beijing 100871, Peoples R China
[4] Natl Res & Dev Ctr Welf & Hlth, STAKES, Helsinki, Finland
[5] Univ Helsinki, Cent Hosp, Dept Paediat, FIN-00014 Helsinki, Finland
[6] Univ Strasbourg, Strasbourg, France
[7] Fdn Community Control Hereditary Dis, Budapest, Hungary
[8] Kaplan Med Ctr, Rehovot, Israel
[9] AO G Rummo, Div Med Genet, Benevento, Italy
[10] Birth Defects Registry, Campania, Italy
[11] Sicily Congenital Malformat Registry, Sicily, Italy
[12] Univ Padua, Dept Paediat, Veneto, Italy
[13] Arzignano Hosp, Paediat Unit, Vicenza, Veneto, Italy
[14] Univ Naples Federico II, Naples, Italy
[15] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Dept Genet, RYVEMCE, Mexico City, DF, Mexico
[16] Univ Groningen, NL-9700 AB Groningen, Netherlands
[17] Moscow Birth Defects Registry, Moscow, Russia
[18] ECEMC, Madrid, Spain
[19] Inst Salud Carlos III, Madrid, Spain
[20] Univ Complutense, E-28040 Madrid, Spain
[21] CDCP, Natl Ctr Environm Hlth, Atlanta, GA USA
[22] CDCP, Natl Ctr Birth Defects & Dev Disabil, Atlanta, GA 30341 USA
[23] Univ Bergen, Bergen, Norway
[24] Int Ctr Birth Defects, Rome, Italy