[1] Univ Leeds, Ctr Reprod Growth & Dev, Leeds, W Yorkshire, England
[2] Christie Hosp NHS Trust, Dept Med Oncol, Manchester M20 4BX, Lancs, England
[3] Christie Hosp NHS Trust, Dept Histopathol, Manchester M20 4BX, Lancs, England
[4] Paterson Inst Canc Res, Dept Canc Genet, Manchester M20 9BX, Lancs, England
[5] St Marys Hosp, Dept Reprod Med, Manchester M13 0JH, Lancs, England
[6] Christie Hosp NHS Trust, Dept Endocrinol, Manchester M20 4BX, Lancs, England