[1] Univ Edinburgh, Western Gen Hosp, Mol Med Ctr, Human Genet Unit, Edinburgh EH4 2XU, Midlothian, Scotland
[2] Aberdeen Royal Infirm, Dept Med Genet, Aberdeen, Scotland
[3] Univ Aberdeen, Aberdeen Matern Hosp, Dept Obstet & Gynaecol, Assisted Reprod Unit, Aberdeen, Scotland