1. Clinical Center of Endocrinology and Gerontology , Medical University, Sofia , Medical Faculty , Sofia , Bulgaria
2. Clinic of Rheumatology , Medical University, Sofia , Medical Faculty , Sofia , Bulgaria
3. National Genetic Laboratory , University Specialized Hospital for Active Treatment in Obstetrics and Gynecology, “Maichin dom”, Medical University, Sofia , Medical Faculty , Sofia , Bulgaria
4. Clinic of Nephrology , Medical University, Sofia , Medical Faculty , Sofia , Bulgaria