This textbook was prepared in accordance with the Federal State Educational Standard of Higher Education for the specialty 31.05.01 General Medicine (2020), the OOP of the specialty 31.05.01 General Medicine (2024), the Curriculum (2024), Working Program of the «Medical Genetics» discipline (2024) for students in the specialty 31.05.01 General Medi-cine and is intended for mastering general professional (GPC-5), professional (PC-5, PC-6, PC-8, PC-11) competencies in accordance with the Federal State Educational Standard. The textbook provides comprehensive information on the etiology, mechanisms of development, classification, clinical manifestations, and diagnosis of chromosomal disorders. Congenital malformations are described using medical terminology essential for any medical professional.