Optimal Approach for Analysis of Case-Control Genetic Association Studies (GALA 1)

March 8, 2013 updated by: University of California, San Francisco

Case-Control Association Studies and Genetic Confounding

The purpose of this study is to examine the effectiveness of approaches to correct for the effects of population stratification on case-control genetic association studies.

Study Overview

Status

Completed

Conditions

Detailed Description

BACKGROUND:

In racially admixed populations, genetic associations may be confounded by population stratification. To control for population stratification, statistical methods that use marker genotype data to infer population structure have been proposed as an alternative to family-based tests of association. However, there are limited empirical data on how these methods perform in real populations. This study will use well characterized populations of Mexican and Puerto Rican asthmatics, their parents, and control subjects recruited from the same sites to examine the effectiveness of approaches to correct for the effects of population stratification on case-control genetic association studies.

DESIGN NARRATIVE:

This study has three specific aims: 1) To test and compare methods of detecting and correcting for population stratification, the study will genotype a total of 100 ancestral informative markers (AIMs) for 400 asthma cases and an equal number of control subjects. These AIMs will then be used with three statistical methods developed to detect and correct for population stratification. The number and characteristics of markers required to correct false positive associations between AIMs, asthma, and asthma quantitative traits will be evaluated and compared; 2) To compare the power of genomically adjusted case-control studies to the Transmission Disequilibrium Test (TDT). An allele from each of the 100 AIMs will be considered as a risk factor for a simulated "phenotype." The association between phenotypes and each AIM will be tested with the TDT and with a case-control analysis after adjustment for stratification to compare the false negative rates for these study designs. 3) To use the results from aim 1 and 2 to define an optimal approach for analysis and interpretation of case-control association studies in these populations and apply this approach to analyze the association between asthma and a series of candidate genes. The results of these studies should provide important insights into optimal methods to control for population stratification in case-control association studies, thereby facilitating the inclusion of admixed populations in future genetic studies of complex diseases such as asthma.

Study Type

Observational

Enrollment (Actual)

800

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • San Francisco, California, United States, 94143
        • University of California, San Francisco

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

8 years to 40 years (Child, Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Family-based cross sectional analysis

Description

No eligibility criteria; this study will be using existing blood samples of Mexican and Puerto Rican asthmatics, their parents, and control participants who were recruited prior to the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Family-Based
  • Time Perspectives: Retrospective

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, San Francisco

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

  • Principal Investigator: Esteban Gonzalez Burchard, MD, University of California School of Medicine, San Francisco

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2005

Primary Completion (Actual)

June 1, 2010

Study Registration Dates

First Submitted

October 17, 2005

First Submitted That Met QC Criteria

October 17, 2005

First Posted (Estimate)

October 19, 2005

Study Record Updates

Last Update Posted (Estimate)

March 11, 2013

Last Update Submitted That Met QC Criteria

March 8, 2013

Last Verified

March 1, 2013

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1309
  • R01HL078885 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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