1. Clinical Center of Endocrinology and Gerontology, Medical Faculty, Sofia Medical University, Sofia, Bulgaria;
2. National Genetic Laboratory, UHOG “Maichin dom”, Medical Faculty, Sofia Medical University, Sofia, Bulgaria;
3. Gynecology and Assisted Reproduction Hospital “Malinov DM”, Sofia, Bulgaria;
4. Department of Biology, Medical Genetics and Microbiology, Faculty of Medicine, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria;
5. Department of Medical Genetics, Sofia Medical University, Sofia, Bulgaria