1. Department of Metabolic Diseases, Jagiellonian University Medical College, Krakow, Poland
2. Krakow University Hospital, Krakow, Poland
3. Department of Medical Education, Jagiellonian University Medical College, Krakow, Poland
4. Section on Genetics and Epidemiology, Joslin Diabetes Center, Boston, Massachusetts, USA
5. Department of Paediatrics, Medical University of Lodz, Lodz, Poland