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Introduction to Molecular Epidemiology. Jan Dorman, PhD University of Pittsburgh School of Nursing jsd@pitt.edu. Science Medicine. Society Epidemiology. Revolution in Molecular Biology has Impacted:. Molecular Epidemiology Challenge for the 21st Century. Molecular Epidemiology.
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Introduction to Molecular Epidemiology Jan Dorman, PhD University of Pittsburgh School of Nursing jsd@pitt.edu
Science Medicine Society Epidemiology Revolution in Molecular Biology has Impacted: Molecular Epidemiology Challenge for the 21st Century
Molecular Epidemiology • Will facilitate the ability of scientists to conduct etiologic research • Will increase our knowledge about the determinants of disease • Will contribute to the development of approaches for disease prevention • Will improve public health
Genetic Epidemiology A science that deals with etiology, distribution and control of disease in families and with inherited causes of diseases in populations N Morton
Genetic Epidemiology • Is based on population genetics • Utilizes statistical techniques to evaluate the genetic aspects of chronic diseases • Little or no emphasis on environmental risk factors
Genetic Epidemiology Includes the fundamental interaction between genetic variation with the environment in the occurrence of disease M Khoury
Genetic Epidemiology • Many studies are still focused on the identification ofdisease susceptibility genes • New SNP and haplotype maps • New approaches to linkage analysis - High through-put molecular techniques
Genetic Epidemiology Results are not generalizable to the population at large Requires Molecular Epidemiology
Origins of Molecular Epidemiology Descriptive and Analytical Epidemiology Infectious Diseases Cancer
Molecular Cancer Epidemiology An approach in which advanced laboratory methods are used with analytical epidemiology to identify, at the biochemical or molecular level, specific exogenous agents and / or host factors that play a role in human cancer causation F. Perera
Traditional Cancer Epidemiology Exposure Disease Black Box Effects of environmental exposures
Molecular Cancer Epidemiology Use of biological markers to examine parts of a continuum between an initiating event and the development of disease Exposure Disease Inside the Black Box
Molecular Epidemiology Genetic Susceptibility Exposure Effect Disease Black Box
Molecular Epidemiology A science that deals with the contribution of genetic and environ-mental risk factors identified at the molecular and biochemical level, to the etiology, distribution and control of disease in families and populations J. Dorman
Molecular Epidemiology • Dissolved boundaries between traditional epidemiology and: • Human genetics • Molecular genetics • Molecular biology • Requires decisions about collecting, processing and storing biological specimens
Molecular Epidemiology • Requires consideration of standardization, analytical validityand clinical validity of molecular tests • Utilizes family study designs, as well as case-control and cohort studies
Molecular Epidemiology Is not just a term that describes adding new techniques to epidemiology. Rather, it represents an opportunity to use new resolving power to develop theories of disease causation that acknowledge complex interactions in the health process. P Schulte
Molecular Epidemiology is a Critical Link Human Genome Project Molecular Epidemiology Medicine and Public Health
Map and sequence ~ 30,000 genes Development of biotechnology Ethical, legal and social issues Map and sequence non-human genomes Markers of disease and susceptibility Technology for population studies Screening and prevention Models for disease, identify susceptibility genes Human Genome Project and Epidemiology
Objectives of Molecular Epidemiology • Conduct descriptive and analytical studies to evaluate gene / environment interactions in disease etiology • Provide risk factor-specific morbidity rates for purposes of education and intervention
Molecular Epidemiology and Disease Prevention • Personalized estimates of risk may empower susceptible individuals to intervene on: • - Diet, lifestyle • - Environmental exposures • Targeted approaches may be more effective in preventing disease
Descriptive Epidemiology • Examines the distribution of disease - By person, place and time - Consequences to population • Rates are expressed as incidence and prevalence (i.e., morbidity rates)
Descriptive Molecular Epidemiology • Assesses effects and / or outcomes early in the disease process • Reduces heterogeneity in disease classification • Examines the distribution of markers of susceptibility or exposure
Analytical Epidemiology • Evaluates associations with potential risk factors • Host characteristics • Environmental exposures • Associations are expressed as relative risks or odds ratios
Analytical Molecular Epidemiology • Utilizes biological markers to replace surrogate measures that have been typically employed for traditional epidemiologic studies • Genetic susceptibility • Environmental exposures or effects
Environmental Risk Factors • Place of residence • Lifestyle / occupational indicators • Biological markers of exposure - Alterations to the host genome - Antibodies - Infectious agents More precise measure of exposure
Genetic Susceptibility • Age, race, sex, ethnic group • Positive family history of the disease • Genetic markers / susceptibility genes - Protein polymorphisms - DNA polymorphisms More precise measure of susceptibility
Evaluating Genes as Effect Modifiers Mutation + Exposure = High Risk Mutation + No Exposure = Low Risk No Mutation + Exposure = Low Risk No Mutation + No Exposure = Low Risk Study Disease Etiology
Evaluating Genes as Susceptibility Markers Mutation + Exposure = High Risk Mutation + No Exposure = Moderate Risk No Mutation + Exposure = Moderate Risk No Mutation + No Exposure = Low Risk Intervene on Susceptibles
Risk Factor-Specific Morbidity Rates Descriptive Analytical Relative risk Absolute risk Population attributable risk
Molecular Epidemiology Requires • Collaboration among: - Epidemiologists - Human geneticists - Environmental health scientists - Health professionals - Biostatisticians - Basic scientists
Challenges for Molecular Epidemiology • Develop and sustain collaboration among individuals with different - Backgrounds - Training - Experience - Goals - Language
Challenges for Molecular Epidemiology Training • Human genetics, molecular biology and environmental health for epidemiologists and health professionals • Epidemiology and public health for human geneticists and basic scientists
Challenges forMolecular Epidemiology • Translations of the results of molecular epidemiology studies • Foster links with: - Members of the community - Policy makers - Educators - General public
Science Medicine Society Epidemiology Revolution in Molecular Biology has Impacted: Molecular Epidemiology Challenge for the 21st Century