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 Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>