Genetic Component of Handedness

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: NCT00005003
Recruitment Status : Completed
First Posted : March 24, 2000
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

Some functions are generally controlled by the right side of the brain and others by the left. One of the most easily observed examples of this "lateral specialization" of the brain is handedness-that is, a person's preference for using either the right or the left hand. This study will try to determine how the genetic component of handedness is inherited. It will test the theory that a single gene is involved in determining handedness and will try to locate the gene.

Families with at least two left-handed siblings aged eight years or older and at least one right-handed parent are eligible to participate in this study.

The left-handed siblings and both parents will fill out a brief questionnaire on hand usage, obtain a tissue sample taken from inside the cheek, and return the questionnaire and the sample by mail to the study researchers. The tissue sample will be used for DNA gene mapping.

Participants will be given a kit and instructions for obtaining the sample, along with mailing envelopes. Cheek swab sampling basically involves using a small brush to gently brush a layer of cells off of the inner wall of the cheek and then dropping the brush tip into a preservative.

The information gained from this study may provide insight into aspects of brain development that can be of medical benefit in the future.

Condition or disease

Detailed Description:
The purpose of this protocol, based on the hypothesis that human hand-use preference (handedness) is largely dependent on the action of a single locus, is to collect samples allowing us to map a "handedness gene" via detection of linkage to any of eight potential candidate genes/regions or via a whole or partial genome scan. We calculate that a full 300 marker genome scan of 100 parents and sibling pairs (allowing linkage analysis at 10 cM resolution), or the equivalent amount of data from partial scans of 300 families, has a high likelihood of allowing us to map the proposed gene. Eligible families, consisting of pairs of left-handed siblings plus at least one right-handed parent, were identified during Phase I of this study in 1996-1998, with approval from the now-lapsed FCRDC IRB. In Phase II of this study, we have collected cheek swab samples for DNA isolation from members of 100 eligible families for use in the mapping studies. DNA samples will not be linked back to individuals but grouped under a random family code that links to a database with limited information, including hand use preference and family structure. In the next phase, we wish to map the locus from cheek swab samples we have on hand.

Study Type : Observational
Enrollment : 1400 participants
Official Title: Mapping the Genetic Component of Hand-Use Preference
Study Start Date : March 2000
Study Completion Date : April 2006

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


Members of families meeting the following criteria are eligible to participate:

Have two left-handed siblings.

Have at least one right-handed parent with no other known left-handed first degree relatives.


All members of a family may be excluded if the right-handed parents or the left-handed siblings will not participate.

Individuals in families whose left-handed siblings are under the age of eight are not eligible to participate.

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): NCT00005003

United States, Maryland
National Cancer Institute (NCI)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Cancer Institute (NCI)

Publications: Identifier: NCT00005003     History of Changes
Other Study ID Numbers: 000094
First Posted: March 24, 2000    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: April 2006

Keywords provided by National Institutes of Health Clinical Center (CC):
High-Frequency-Trait Analysis