Featured Research

from universities, journals, and other organizations

Hypertension In African Americans Linked To Two Genomic Regions

Date:
February 20, 2005
Source:
Washington University School Of Medicine
Summary:
A first-of-its-kind application of a novel statistical method of analysis to African Americans has identified regions on chromosomes 6 and 21 that likely harbor genes contributing to high blood pressure in that group. The novel statistical method, called admixture mapping, narrowed the search for genes related to hypertension, bringing researchers and doctors closer to finding more effective treatments.

Feb. 9, 2005 — A first-of-its-kind application of a novel statistical method of analysis to African Americans has identified regions on chromosomes 6 and 21 that likely harbor genes contributing to high blood pressure in that group. The novel statistical method, called admixture mapping, narrowed the search for genes related to hypertension, bringing researchers and doctors closer to finding more effective treatments.

Researchers at Stanford University School of Medicine, Loyola University Medical Center and Washington University School of Medicine in St. Louis, among others, collaboratively conducted the study, which will be published in the February issue of Nature Genetics and is available online.

In the U.S., 65 million people have high blood pressure, but it is found more often in African Americans than other groups. African Americans suffer from earlier and more severe hypertension and have a higher rate of death from stroke, heart disease, and kidney failure as a result.

The causes of hypertension are complex. Diet, exercise and stress contribute, but so do genetic factors. "It wouldn't be surprising if hypertension involved dozens of genes," says Dabeeru C. Rao, Ph.D., director of the Division of Biostatistics and one of the report's authors. "Unfortunately, in the past there have been conflicting reports about genes linked to the condition."

In a fresh approach to the problem, the researchers applied a genome-wide scan that compared how often genetic variations occur in people of African or European descent to how often they occur in African Americans.

As a group, African Americans can trace their ancestry largely to populations from both Africa and Europe. "The statistical technique we used is ideal for groups who have a trait with a higher occurrence—such as hypertension in African Americans—and who stem from two sets of ancestral populations that have differing genetic variations," Rao says.

"The admixture mapping method has distinct advantages over other more commonly used methods for population analysis," says C. Charles Gu, Ph.D., assistant professor of biostatistics and a co-author of the report. "We looked for genomic regions with an 'excess of ancestry' from one of the two populations. In this case we looked for excess ancestry from the African population, because it has a higher frequency of genes contributing to high blood pressure." Excess of ancestry is a term indicating the genomic region in African Americans is derived more often from one ancestral population than the other.

The researchers looked at the distribution of 269 genetic markers across the genome in each of the three groups. Compared to African Americans without high blood pressure, African Americans with high blood pressure were more likely to have a distribution of markers—in the identified genomic regions—resembling that of the African (ancestral) group.

The excess African ancestry among people with high blood pressure enabled the researchers to find two locations, one on chromosome 6 and one on chromosome 21, that stood out with the strongest association to high blood pressure in African Americans. Other markers close by on the same chromosomes also had a strong association with high blood pressure, indicating that the chromosome regions near these two groups of markers probably contain genes responsible for an increased risk of hypertension.

Researchers can now use this information to help locate genes affecting hypertension. "When a specific gene variant associated with hypertension is identified, physicians will be able to test patients for their risk of hypertension to head it off early," Rao says. "In addition, research institutions and pharmaceutical companies can develop new drugs that compensate for the effect of that gene."

Data used in the study came from the U.S. National Heart, Lung and Blood Institute's Family Blood Pressure Program and the International Collaborative Study on Hypertension in Blacks.

The Division of Biostatistics at Washington University serves as the Program Data Center for the Family Blood Pressure Program, which involves twenty institutions, including those participating in this project. The division pools and integrates data from across different study centers and makes the data available to all the participants. It will build a web-based system to open the data to the public. This particular project was led by Neil Risch at Stanford and the analysis was led by Xiofeng Zhu at Loyola.

###

Zhu X, Luke A, Cooper RS, Quetermous T, Hanis C, Mosley T, Gu CC, Tang H, Rao DC, Risch N, Weder A. Admixture mapping for hypertension loci with genome-scan markers. Nature Genetics, 2005 Feb;37(2):177-181.

Funding from the U.S. National Heart, Lung and Blood Institute supported this research.

Washington University School of Medicine's full-time and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked second in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.


Story Source:

The above story is based on materials provided by Washington University School Of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Washington University School Of Medicine. "Hypertension In African Americans Linked To Two Genomic Regions." ScienceDaily. ScienceDaily, 20 February 2005. <www.sciencedaily.com/releases/2005/02/050212185123.htm>.
Washington University School Of Medicine. (2005, February 20). Hypertension In African Americans Linked To Two Genomic Regions. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2005/02/050212185123.htm
Washington University School Of Medicine. "Hypertension In African Americans Linked To Two Genomic Regions." ScienceDaily. www.sciencedaily.com/releases/2005/02/050212185123.htm (accessed October 2, 2014).

Share This



More Health & Medicine News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Might Not Be Out Of Control In U.S., But Coverage Is

Ebola Might Not Be Out Of Control In U.S., But Coverage Is

Newsy (Oct. 2, 2014) Coverage of the lone Ebola patient discovered in Texas has U.S. media in a frenzy — but does the coverage match the reality? Video provided by Newsy
Powered by NewsLook.com
US Hunts Contacts of Ebola Patient, Including Children

US Hunts Contacts of Ebola Patient, Including Children

AFP (Oct. 2, 2014) Health officials in Texas on Wednesday scoured the Dallas area for people, including schoolchildren, who came in contact with a Liberian man who was diagnosed with Ebola in the United States. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Study Says Losing Sense Of Smell Can Indicate Death

Study Says Losing Sense Of Smell Can Indicate Death

Newsy (Oct. 2, 2014) Researchers found elderly adults with a poor sense of smell are more likely to die within five years. Video provided by Newsy
Powered by NewsLook.com
Pregnancy Spacing Could Have Big Impact On Autism Risks

Pregnancy Spacing Could Have Big Impact On Autism Risks

Newsy (Oct. 1, 2014) A new study says children born less than one year and more than five years after a sibling can have an increased risk for autism. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins