Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Genome-wide Association Studies-GWAS01:11

Genome-wide Association Studies-GWAS

12.2K
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
12.2K
Hardy-Weinberg Principle01:49

Hardy-Weinberg Principle

62.0K
Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the gene pool of the population. The gene pool of a population is the sum of every allele of all genes within that population and has some degree of variation. Genetic variation is typically expressed as a relative frequency, which is the percentage of the total population that has a given allele, genotype or phenotype.
62.0K
Test for Homogeneity01:23

Test for Homogeneity

1.7K
The goodness–of–fit test can be used to decide whether a population fits a given distribution, but it will not suffice to decide whether two populations follow the same unknown distribution. A different test, called the test for homogeneity, can be used to conclude whether two populations have the same distribution. To calculate the test statistic for a test for homogeneity, follow the same procedure as with the test of independence. The hypotheses for the test for homogeneity can...
1.7K
Genetic Lingo01:11

Genetic Lingo

84.0K
Overview
84.0K
Genetic Variation01:25

Genetic Variation

1.6K
Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity.
Genes exist in different versions called alleles,...
1.6K
Multiple Allele Traits01:49

Multiple Allele Traits

32.4K
The Concept of Multiple Allelism
32.4K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Atypical energy-related symptoms define biologically distinct subtypes of major depressive disorder.

medRxiv : the preprint server for health sciences·2026
Same author

Metabolomic ageing across mental and behavioural disorders.

BMJ mental health·2026
Same author

Trans-ancestry genome-wide association meta-analysis of antidepressant response to selective serotonin reuptake inhibitors in clinical studies of depression.

medRxiv : the preprint server for health sciences·2026
Same author

Metabolomic ageing (MileAge) in mid-life predicts incident vascular, unspecified and all-cause dementia.

Alzheimer's & dementia : the journal of the Alzheimer's Association·2026
Same author

Treatment resistant depression in electronic health records: definitions matter.

BMC psychiatry·2026
Same author

Impact of depression on treatment progression in type 2 diabetes: A UK retrospective cohort study using the Clinical Practice Research Datalink Aurum database.

Primary care diabetes·2026

Related Experiment Video

Updated: Apr 23, 2026

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
05:53

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry

Published on: June 21, 2018

9.2K

Homogeneous case subgroups increase power in genetic association studies.

Matthew Traylor1, Hugh Markus1, Cathryn M Lewis2

  • 1Clinical Neurosciences, University of Cambridge, Cambridge, UK.

European Journal of Human Genetics : EJHG
|October 2, 2014
PubMed
Summary

Analyzing genetically homogeneous subgroups in genome-wide association studies (GWAS) can increase power to detect disease-associated variants. This strategy is particularly effective for identifying rarer variants with modest effects, uncovering hidden heritability in complex disorders.

More Related Videos

Large-Scale Multi-Omics Genome-Wide Association Studies Mo-GWAS: Guidelines for Sample Preparation and Normalization
08:27

Large-Scale Multi-Omics Genome-Wide Association Studies Mo-GWAS: Guidelines for Sample Preparation and Normalization

Published on: July 27, 2021

4.6K
An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations
10:17

An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations

Published on: November 3, 2010

23.3K

Related Experiment Videos

Last Updated: Apr 23, 2026

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
05:53

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry

Published on: June 21, 2018

9.2K
Large-Scale Multi-Omics Genome-Wide Association Studies Mo-GWAS: Guidelines for Sample Preparation and Normalization
08:27

Large-Scale Multi-Omics Genome-Wide Association Studies Mo-GWAS: Guidelines for Sample Preparation and Normalization

Published on: July 27, 2021

4.6K
An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations
10:17

An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations

Published on: November 3, 2010

23.3K

Area of Science:

  • Genetics
  • Bioinformatics
  • Disease Research

Background:

  • Genome-wide association studies (GWAS) have advanced disease genetics using broad clinical definitions.
  • Limitations exist in simple clinical definitions, prompting exploration of refined phenotypes within existing GWAS data.
  • Current subgroup analyses are often ad hoc, lacking power considerations.

Purpose of the Study:

  • To derive expressions for the relative power of subgroup analyses in GWAS.
  • To determine the genotypic relative risks (GRRs) needed for equivalent power to full analyses.
  • To assess the potential of genetically homogeneous subgroups for identifying novel genetic associations.

Main Methods:

  • Derivation of mathematical expressions for the relative power of subgroup analyses.
  • Calculation of required genotypic relative risks (GRRs) for subgroup analyses to match full analysis power.
  • Analysis of power differences based on variant frequency (rare vs. common) and effect size (GRR).

Main Results:

  • Modest increases in GRRs can offset power reductions from analyzing fewer cases in subgroups.
  • Genetically homogeneous case subgroups show potential for identifying additional genetic associations.
  • Subgroup analyses offer relatively more power for lower GRRs and rare variants compared to higher GRRs and common variants.

Conclusions:

  • Renewed efforts to define phenotypically homogeneous disease groups are advocated for GWAS.
  • Analyzing case subsets is a powerful strategy for uncovering hidden heritability in complex disorders.
  • This approach is especially promising for detecting rarer variants with modest effects.