Genetic factors

Genetic epidemiology studies the role of genetic factors and their interaction with environmental factors in the occurrence of disease in human populations. A brief introduction to human genetics was given. Several methods used in genetic epidemiology were described, such as familial aggregation (population and family studies), the segregation of a disease, association studies to evaluate the association between the risk of a disease (or trait) and the genetic factor (marker, allele) in cases and controls. Linkage analysis studies the cosegregation of the disease with a gene. After assessing information on the genomic localization of the disease gene(s), the process of identifying the exact disease gene can be performed by molecular biologists. In this chapter the role played by genetic factors in asthma, atopy, chronic obstructive pulmonary disease, α1-antitrypsin-deficiency (AAT-deficiency), cystic fibrosis, lung cancer and spontaneous pneumothorax were summarized. Genetic epidemiological studies result in growing knowledge and understanding of the aetiology and pathology of diseases in human populations with the ultimate goal of disease control and prevention. Genetic epidemiology covers a large area of interest and has implications for both clinical medicine as well for public health.