[1] Newcastle Univ, Fac Med Sci, Populat Hlth Sci Inst, Baddiley Clark Bldg,Richardson Rd, Newcastle Upon Tyne NE2 4AX, Tyne & Wear, England
[2] Inst Clin Physiol, Natl Res Council, Unit Epidemiol Rare Dis & Congenital Anomalies, Pisa, Italy
[3] Fdn Toscana Gabriele Monasterio, Pisa, Italy
[4] St Georges Univ London, Populat Hlth Res Inst, London, England
[5] Hosp Lillebaelt, Pediat Dept, Kolding, Denmark
[6] Ulster Univ, Fac Life & Hlth Sci, Coleraine, Londonderry, North Ireland
[7] Fdn Promot Hlth & Biomed Res Valencian Reg, Rare Dis Res Unit, Valencia, Spain
[8] Univ Groningen, Univ Med Ctr Groningen, Dept Genet, Groningen, Netherlands
[9] Directorate Hlth Informat & Res, Malta Congenital Anomalies Registry, Tal Pieta, Malta
[10] THL Finnish Inst Hlth & Welf, Informat Serv Dept, Helsinki, Finland
[11] Univ Paris, Ctr Res Epidemiol & Stat CRESS, INSERM INRA, Obstetr Perinatal & Pediat Epidemiol Res Team EPO, Paris, France
[12] Univ Bergen, Dept Global Publ Hlth & Primary Care, Bergen, Norway
[13] Norwegian Inst Publ Hlth, Div Mental & Phys Hlth, Bergen, Norway
[14] Univ Ferrara, Ctr Clin & Epidemiol Res, Ferrara, Italy
[15] Swansea Univ, Fac Hlth & Life Sci, Swansea, W Glam, Wales
[16] Publ Hlth Wales, Swansea, W Glam, Wales
[17] Princess Anne Hosp, Wessex Clin Genet Serv, Southampton, Hants, England