Related Experiment Video
Updated: Jun 30, 2026
08:09
Gene-environment Interaction Models to Unmask Susceptibility Mechanisms in Parkinson's Disease
Published on: January 7, 2014
Bias in association studies resulting from gene-environment interactions and competing risks
Alexis Elbaz1, Annick Alpérovitch
1Institut National de la Santé et de la Recherche Médicale (INSERM), Unit 360, Paris, France. alexis.elbaz@chups.jussieu.fr
American Journal of Epidemiology
|February 1, 2002
Summary
Competing risks can bias genetic susceptibility studies for late-onset diseases. Omitting interacting environmental factors, especially those linked to death, can create confounding bias in genetic risk assessments.
Area of Science:
- Epidemiology
- Genetic Epidemiology
- Biostatistics
Background:
- Multifactorial late-onset diseases are extensively studied for their genetic basis.
- Understanding genetic susceptibility is crucial for disease etiology research.
Purpose of the Study:
- To investigate how competing risks introduce bias in genetic susceptibility studies for late-onset diseases.
- To identify conditions under which confounding bias arises due to competing risks.
Main Methods:
- Utilized an epidemiologic modeling framework.
- Analyzed scenarios involving interacting genetic and environmental risk factors.
- Incorporated competing risks of death into the model.
Main Results:
- Bias in genetic association measures occurs when an environmental factor, interacting with a genetic factor to cause death, is omitted.
- This bias is a form of confounding, stemming from time-dependent associations.
- Numerical examples demonstrate that bias can be substantial under specific conditions.
Conclusions:
- Researchers studying late-onset diseases must consider competing risks of death.
- Awareness of potential confounding bias is essential for accurate genetic susceptibility research in older populations.
Related Concept Videos
02:27Background and Environment Affect Phenotype
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
01:09Epistasis Analysis
Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of phenotypes. When the interaction of various genes or alleles at different locations influences a phenotype, this is called epistasis. Epistasis often involves one gene masking or interfering with the expression of another (antagonistic epistasis). Epistasis often occurs when different genes are part of the same biochemical pathway. The...
01:22Bias
Bias refers to any tendency that prevents a question from being considered unprejudiced. In research, bias occurs when one outcome or answer is selected or encouraged over others in sampling or testing. Bias can occur during any research phase, including study design, data collection, analysis, and publication.
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...
01:27Confounding in Epidemiological Studies
Confounding in statistical epidemiology represents a pivotal challenge, referring to the distortion in the perceived relationship between an exposure and an outcome due to the presence of a third variable, known as a confounder. This variable is associated with both the exposure and the outcome but is not a direct link in their causal chain. Its presence can lead to erroneous interpretations of the exposure's effect, either exaggerating or underestimating the true association. This phenomenon...
01:29Bias in Epidemiological Studies
Biases can arise at various stages of research, from study design and data collection to analysis and interpretation. Recognizing and addressing these biases is essential to ensure the validity and reliability of epidemiological findings.Broadly speaking, biases in epidemiology fall into three main categories: selection bias, information bias, and confounding. A more detailed description of possible biases is:
01:20Gene-Environment Interactions
Gene expression is a dynamic process that is significantly influenced by environmental factors. This interaction underlies the complex nature of biological development and the phenotypic differences observed among individuals, even among those with identical genetic makeups. Factors such as radiation, temperature, behavior, nutrition, and stress play pivotal roles in determining how genes are expressed. The concept of the reaction range is central to understanding this interaction. It posits...