Nature Genet. 32, 384–392 (2002).

Published online 7 October 2002; corrected 21 October 2002 (details online); doi:10.1038/ng1002

The affiliation of B. Lemcke appeared incorrectly. The correct affiliation for B. Lemcke is Institut für Humangenetik, Universität Münster, Münster, Germany.