|
Research question/problem | Type of study | Unit of study | Type of measurement | Aim |
|
Is there evidence of phenotypic aggregation within families? | Familial aggregation | Case-parent Case-parent-grandparent | Recurrence risk ratio Correlation Odds ratio Conditional regression logistic | Identifying new disease genes |
|
Is the pattern of aggregation reliable with an effect of genes? | Heritability | Twin study | Variance component heritability | Identifying new disease genes |
|
Is there evidence of a gene with subnational enough effects to justify expensive studies? | Segregation | Familial pedigree | Maximum likelihood estimation Binomial distribution | Identifying new disease genes |
|
Where in the genome is a causative gene most likely to lie? | Linkage | Case; disease of interest and control group; disease-free | Parametric: maximum likelihood Nonparametric: mean, proportion, chi square, likelihood test | Identifying new disease genes |
|
Is there a causative polymorphism? | Association Linkage disequilibrium Cohort Case only study | Related—case control Unrelated-case control Exposure and non-exposure group Case groups | Transmission disequilibrium test Chi square independence Odds ratio Conditional regression logistic Correlation Lewontine’s D prime Relative risk, Attributable risk Exposure odds ratio estimate | Characterizing known disease genes |
|
Estimate allele frequency | Cross-sectional | | Prevalence Correlation | Characterizing known disease genes |
|
Estimating penetrance | Association Cohort | Related—case control Familial cohort | Odds ratio Conditional regression logistic Risk ratio Attributable risk | Characterizing known disease genes |
|
Evaluating strategies for prevention of genetic diseases | Experimental Retrospective cohort | Clinical trial (intervention and control group) Exposure and non-exposure groups | Risk ratio Attributable risk Risk ratio Attributable risk | Characterizing known disease genes |
|