[1] Univ Bern, Inselspital, Dept Obstet & Gynecol, Bern, Switzerland
[2] Univ Bern, Inselspital, Dept Pediat, Div Human Genet, Bern, Switzerland
[3] Univ Helsinki, Folkhalsan Inst Genet, Helsinki, Finland
[4] Praxis Humangenet, Paul Ehrlich Str 22, DE-72076 Tubingen, Germany