Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neutralizing spurious associations

09.02.2009
Statistical analysis helps the search for fundamental causes of disease. Most Japanese people fall into one of two distinct groups genetically, biostatisticians from RIKEN’s Center for Genomic Medicine in Yokohama have shown.

The finding is significant because such population structure can bias genome-wide association studies (GWASs) aimed at determining genetic links to disease, leading to spurious associations. On the basis of their work the researchers suggest ways of avoiding or correcting this bias.

GWASs are increasingly employed to reveal relationships between single nucleotide polymorphisms (SNPs) and particular disease conditions. The technique seeks out statistical differences among sets of polymorphic genetic markers between sufferers of a disease and a control group.

It has already supplied useful information about the genetic basis of asthma, cancer, diabetes, heart disease and mental illness. GWASs, however, assume that the two groups being compared are drawn from the same homogeneous population—that is, there is no underlying pattern of genetic difference between them other than susceptibility to the disease condition being tested.

Although the population as a whole does not show great genetic diversity, previous work by other researchers suggested that the Japanese fall into two genetic categories, perhaps reflecting two migration events. But these studies were of limited regions of the genome. So the RIKEN researchers embarked on a much broader investigation with greater relevance to GWASs. They published their results in a recent issue of The American Journal of Human Genetics (1).

Given the good quality of SNP data on the Japanese population, the researchers used statistical techniques mainly based on principal components analysis to check the homogeneity of genetic structure in a sample of 7,003 people drawn from all over Japan. They found strong evidence of the dual nature of the Japanese population. One genetic group, the Hondo cluster, includes most people from the main islands of Japan; the other, the much smaller Ryukyu cluster, includes most individuals from Okinawa and nearby islands.

The research also demonstrated how such population stratification could impact the results of GWASs using Japanese subjects. As a consequence, the researchers propose measures to avoid bias, such as excluding members from the Ryukyu cluster if they occur in small proportion, equalizing Ryukyu numbers in both disease and control groups, or using statistical techniques to compensate for any potential bias.

“The aim of our analysis is to improve methods for conducting GWASs,” says first author Yumi Yamaguchi-Kabata. “We now wish to broaden the work to encompass different local regions in Asia.”

Reference

1. Yamaguchi-Kabata, Y., Nakazono, K., Takahashi, A., Saito, S., Hosono, N., Kubo, M., Nakamura, Y. & Kamatani, N. Japanese population structure, based on SNP genotypes from 7003 individuals compared to other ethnic groups: Effects on population-based association studies. The American Journal of Human Genetics 83, 445–456 (2008).

The corresponding author for this highlight is based at the RIKEN Laboratory for Statistical Analysis

Saeko Okada | ResearchSEA
Further information:
http://www.rikenresearch.riken.jp/research/633/
http://www.researchsea.com

More articles from Life Sciences:

nachricht Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology

nachricht The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>