[1] Austrian Acad Sci IMBA, Inst Mol Biotechnol, A-1030 Vienna, Austria
[2] Univ Edinburgh, Inst Genet & Mol Med, MRC Human Genet Unit, Edinburgh EH4 2XU, Midlothian, Scotland
[3] Wellcome Trust Sanger Inst, Cambridge CB10 1SA, England
[4] St Georges Univ, Dept Clin Genet, London SW17 0RE, England