Clinical genetics encompasses studies of the role played by inherited and acquired genetic changes in the causation of human diseases. The research and educational activities are intimately integrated with the clinical work at the Department of Clinical Genetics at the University Hospital in Lund, providing genetic counseling, consultation and diagnostic service. The very rapid development of powerful new methodologies in cytogenetics and molecular genetics during recent years has led to a dramatic increase in our knowledge of the importance of genetic factors in the etiology of various disorders, including common diseases such as cancer and cardiovascular disorders. At the same time, a steadily increasing number of such disorders can now also be diagnosed with great precision, even at a presymptomatic stage. Clinical genetics has thus become an increasingly important discipline within the health care system. Because disorders determined by genetic factors affect all organ systems and individuals of all age groups, the patients may be found in all medical specialties. Hence, clinical genetics interacts with many other fields of medical sciences, such as cell biology, biochemistry, pediatrics, gynecology, neurology, hematology and oncology.