Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic Diversity Of European Americans And Disease Gene Mapping

18.01.2008
Labels such as “European American”, “white”, or “Caucasian” are often viewed as representing a homogeneous category in gene mapping studies and census reports, but each of these labels actually groups together multiple populations, which have diverse origins due to the complex history of European immigration to the United States.

In a recent study, published in the open-access journal PLoS Genetics, an international team of researchers provide the first genetic dissection of the population structure of European Americans, focusing on identifying the contributions from different genetic ancestries that are important for disease gene mapping.

This is a timely issue as the last year has seen a dramatic upswing in genetic association studies and the discovery of almost a hundred new risk factors for common genetic diseases such as cancer and diabetes. If the subtle population substructure that exists within European American populations is not understood and accounted for, genetic association studies can produce incorrect findings if disease cases are compared to healthy controls that on average have different ancestry.

By systematically examining data from four actual disease association studies in European Americans, this study describes and characterizes the majority of population substructure in European Americans that could lead to spurious associations. “Although our work is far from a complete description of European American population history, for the purpose of disease gene mapping studies it is adequate to measure how closely each person’s genetic ancestry resembles three populations that can be roughly described as northwest European, southeast European, or Ashkenazi Jewish,” says Dr. David Reich, one of the senior authors on the study, an Associate Professor of Genetics at Harvard Medical School and an Associate Member at the Broad Institute of Harvard and MIT. “With this approach, we can avoid most false-positive associations due to population substructure in European American disease gene mapping studies. Our previous work has addressed related challenges in studies of African Americans and Latino Americans.”

... more about:
»Associate »Association »Genetic »Harvard »ancestry

Based on their discovery that ancestry from only three populations accounts for most of the potentially problematic substructure in European American disease association studies, the researchers scoured through published data sets to identify places in the genome where common DNA sequence variants differ substantially in frequency among these three ancestral populations and are therefore potentially informative for estimating genetic ancestry. The investigators then confirmed the utility of these genetic variants by testing them in DNA samples that their coauthors collected from the United Kingdom, Sweden, Poland, Spain, Italy, Greece and U.S. Ashkenazi Jews. “We identified 300 common genetic variants that have unusually different frequencies in the three ancestral populations: they are about 10 times more informative for predicting the ancestry of European Americans than random genetic variants”, says lead author Dr. Alkes Price, a post-doctoral researcher at the Harvard Medical School Department of Genetics and the Broad Institute of Harvard and MIT. “We can thus correct for population substructure in European American disease association studies using just these 300 markers.”

This panel of 300 markers should be valuable in targeted associated studies that follow up previously implicated candidate genes: by comparing the ancestry of disease cases to healthy controls using data from the panel of 300 markers, researchers can determine whether observed associations are genuine, and not false-positives due to population structure. The panel can also be used to match the ancestry of cases and controls prior to more comprehensive studies.

While the technology should provide a new tool in disease gene mapping studies, the researchers caution that the ability to roughly categorize individuals into populations with a small number of genetic markers is not useful in a clinical setting, nor does it completely eliminate the utility of self-described ethnicity. “Although these 300 markers give a reasonable estimate of the major components of genetic ancestry in European Americans, self-described ethnicity can still reflect environmental, social and cultural factors that may not be captured by estimating genetic ancestry,” says Dr. Joel Hirschhorn, one of the senior authors of the study, an Associate Professor of Genetics at Children's Hospital Boston and Harvard Medical School, and a Senior Associate Member at the Broad Institute of Harvard and MIT, “Because the genetic differences between these populations are very small, the study is most important for helping in gene discovery efforts, which will lead to better understanding of human biology in health and disease, and hopefully improved care for all patients over the long term.”

Andrew Hyde | alfa
Further information:
http://genetics.plos.org

Further reports about: Associate Association Genetic Harvard ancestry

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>