1. Institute for Human Genetics, RWTH Aachen University , Aachen , Germany
2. LADR Laborzentrum Recklinghausen , Recklinghausen , Germany
3. Foundation for Disabled Children, Stiftung für das behinderte Kind , Bonn , Germany
4. Division of Human Genetics, Medical University Innsbruck , Innsbruck , Austria
5. University Hospital Bonn , Bonn , Germany