1. Department of Clinical Genetics, Oulu University Hospital, 90029 Oulu, Finland.
2. Department of Internal Medicine, Oulu University Hospital, 90029 Oulu, Finland.
3. Department of Medical Genetics, Molecular and Cancer Biology Research Program, 00014 University of Helsinki, Helsinki, Finland.
4. Department of Pathology, University of Oulu, 90014 Oulu, Finland.
5. Medical Department III, Leipzig University, 04103 Leipzig, Germany.