COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

Enhanced Linkage Maps From Family-Based Genetics Studies

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00049868
Recruitment Status : Completed
First Posted : November 15, 2002
Last Update Posted : September 25, 2020
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by:
Rutgers, The State University of New Jersey

Brief Summary:
To develop genetic maps for the genome-wide screening markers used by multiple investigators and to investigate map differences between sexes and different ethnic groups.

Condition or disease
Cardiovascular Diseases

Detailed Description:


Meiotic linkage maps are the foundation of both linkage and linkage disequilibrium studies for mapping disease genes. Despite the importance of precise maps, existing genome-wide linkage maps were built using only a small collection of pedigrees, and so have wide confidence intervals surrounding estimates of map distance. Incorrect marker order and map distances can have a profound effect on linkage analyses. Using a sex-averaged map instead of a sex-specific map biases the lod scores upward, markedly increasing the false positive rate. Since it is very costly to follow-up many false-positive results, there is a clear need for more precise and accurate sex-specific genetic maps. Accurate estimates of meiotic map distance cannot be obtained by any means other than by linkage analysis using genotype data.

The study is in response to a Request for Applications entitled "NHLBI Innovative Research Grant Program" released in July, 2001. The purpose of the initiative is to support new approaches to heart, lung, and blood diseases and sleep disorders that use existing data sets or existing biological specimen collections whether obtained through National Heart, Lung, and Blood Institute support or not.


The genetic epidemiology study will build improved highly-precise sex-specific linkage maps utilizing thousands of individuals who have previously been genotyped. After filtering out obvious relationship and genotype errors, the study will incorporate methods that properly model for genotyping errors. In addition to creating precise maps for the scientific community, the study will also use these genotype data to study how recombination may vary between ethnic groups. The genotypes generated by the NHLBI Mammalian Genotyping Service are precisely the type of data required to produce more accurate maps. These data collections contain over 3,400 pedigrees with more than a 100-fold increase in information compared to that contained in the 8 CEPH families that have been used to construct current genome-wide linkage maps. The new maps will be made publicly available and the genotype data from the study will be accessible by the MAP-0-MAT linkage mapping server. In the future, the study will be broadened to incorporate genotype data from additional genotyping centers such as the Center for Inherited Disease Research (CIDR).

Layout table for study information
Study Type : Observational
Actual Enrollment : 1 participants
Observational Model: Other
Time Perspective: Other
Study Start Date : September 2002
Study Completion Date : August 2005

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   up to 100 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
No eligibility criteria

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00049868

Sponsors and Collaborators
Rutgers University
National Heart, Lung, and Blood Institute (NHLBI)
Layout table for investigator information
OverallOfficial: Tara Matise Rutgers, The State University of New Jersey
Layout table for additonal information Identifier: NCT00049868    
Other Study ID Numbers: 1203
R01HL071029 ( U.S. NIH Grant/Contract )
First Posted: November 15, 2002    Key Record Dates
Last Update Posted: September 25, 2020
Last Verified: September 2020
Additional relevant MeSH terms:
Layout table for MeSH terms
Cardiovascular Diseases