In guidance the substantive provisions of modern medical genetics and possibility of their use are described in clinical practice. Description of material bases of heredity is given in the first part. It is shown, as ideas changed about genes, their organization and work, methods of packing of genetic material in cages, his inherited transmission among generations. Separate heads are sanctified to the types of inheritance of signs, to description of mutations, genetic bases of development, description of genetic structure and dynamics of populations, эпигенетическим modifications, results of international project "Genome of man" and their value for development of molecular medicine. The second part of book is wholly sanctified to the problems and methods of medical genetics. The detailed description of innate teratosiss, chromosomal and monogenic illnesses classified is Given on the types of inheritance. The role of genetic constituents in etiology of multivariable illnesses, possibility of authentication and clinical interpretation of genetic risk factors predisposing to their development comes into question. Bases of phamacogenetics and genetic theory of канцерогенеза are expounded. A separate head is sanctified to the questions of diagnostics and prophylaxis, and also treatments of the inherited and innate diseases. A book is supplied by the dictionary of genetic terms.Guidance is intended for students, interns, interns and graduate students of medical institutions of higher learning, and also the practical doctors, interested in the questions of clinical genetics.