Genetic epidemiology

Genetic epidemiology is the study of the role of genetic factors in determining health and disease in families and in populations, and the interplay of such genetic factors with environmental factors. Genetic epidemiology seeks to derive a statistical and quantitative analysis of how genetics work in large groups. The use of the term Genetic epidemiology emerged in the mid-1980s as a new scientific field. In formal language, genetic epidemiology was defined by Newton Morton, one of the pioneers of the field, as "a science which deals with the etiology, distribution, and control of disease in groups of relatives and with inherited causes of disease in populations". It is closely allied to both molecular epidemiology and statistical genetics, but these overlapping fields each have distinct emphases, societies and journals. One definition of the field closely follows that of behavior genetics, defining genetic epidemiology as "the scientific discipline that deals with the analysis of the familial distribution of traits, with a view to understanding any possible genetic basis", and that "seeks to understand both the genetic and environmental factors and how they interact to produce various diseases and traits in humans". The BMJ adopts a similar definition, "Genetic epidemiology is the study of the aetiology, distribution, and control of disease in groups of relatives and of inherited causes of disease in populations." As early as the 4th century BC, Hippocrates suggested in his essay "On Airs, Waters, and Places" that factors such as behavior and environment may play a role in disease. Epidemiology entered a more systematic phase with the work of John Graunt, who in 1662 tried to quantify mortality in London using a statistical approach, tabulating various factors he thought played a role in mortality rates. John Snow is considered to be the father of epidemiology, and was the first to use statistics to discover and target the cause of disease, specifically of cholera outbreaks in 1854 in London.