<p>As medical science advances, the implementation of medical genetics is required in all areas of medicine. Genetic information has the following characteristics: 1) it does not change throughout a person's life, 2) it can predict the incidence of diseases, 3) it can affect blood relatives, and 4) it has inherent ambiguity. Therefore, care must be taken in handling this information. The Department of Medical Genetics specializes in handling genetic information. The Institute of Medical Genetics was established at Tokyo Women's Medical University in 2004. The important roles of our institute can be summarized as 1) providing genetic counseling; 2) providing accurate diagnosis and appropriate testing for hereditary diseases and congenital syndromes, including cancer; and 3) serving as a hub for routine management and medical care for people with hereditary diseases or congenital syndromes. Secondary findings may be found as a result of comprehensive genomic analyses, such as whole-genome sequencing and whole-exon sequencing. Genetic counseling is the process of helping people understand and adjust to the medical, psychological, and familial implications of a disease with genetic involvement. Thus, it is necessary for all physicians to have genetic counseling as part of their standard knowledge. Furthermore, medical geneticists and genetic counselors provide appropriate genetic counseling in a team setting for clients in the Department of Medical Genetics.</p>