1. Genetic Laboratory, Gynecology and Assisted Reproduction Hospital “Dr Malinov D.M.”, Sofia, Bulgaria;
2. Department of Biology, Medical Genetics and Microbiology, Faculty of Medicine, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria;
3. Department of Paediatrics and Medical Genetics, St. George University Hospital, Medical University - Plovdiv, Plovdiv, Bulgaria;
4. National Genetic Laboratory, University Hospital of Obstetrics and Gynecology “Maichin dom”, Medical University of Sofia, Sofia, Bulgaria;
5. Department of Medical Genetics, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria