1. Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, Brussels, Belgium
2. Department of Public Health and Primary Care, Environment and Health/Youth Health Care, KU Leuven, Kapucijnenvoer 35, Leuven, Belgium
3. Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, Brussels, Belgium