Featured Research

from universities, journals, and other organizations

Novel type 2 diabetes genetic study involves five major ancestry groups

Date:
November 8, 2012
Source:
American Society of Human Genetics
Summary:
A consortium of scientists is taking a novel approach to detect the genetic variations that predispose individuals to type 2 diabetes. The 10,000 individuals (patients and controls) whose exomes, the 18,000 protein-coding genes, are from five major ancestry groups: African-American, East Asian, European, Hispanic and South Asian.

A consortium of scientists who are taking a novel approach in their research to detect the genetic variations that predispose individuals to type 2 diabetes provided an update of their findings at the American Society of Human Genetics (ASHG) 2012 meeting.

Among the project's novel characteristics is the ethnic diversity of the 10,000 individuals whose exomes, the 18,000 protein-coding genes, are being sequenced.

The researchers recruited 5,000 individuals with type 2 diabetes (T2D) from five major ancestry groups: African-American, East Asian, European, Hispanic and South Asian. The study population also includes an equal number of controls, individuals from these same ancestry groups who do not have T2D.

"Our hypothesis is that screening the exome in a range of diverse ethnic groups increases the range of variants of each gene surveyed, and thereby improves our ability to detect genes showing differences in the patterns of the DNA codes for proteins between individuals with type 2 diabetes and controls," said T.M. Teslovich, Ph.D., research fellow in statistical genetics at the University of Michigan, who presented the study at ASHG 2012.

The study is one of the three projects under the umbrella of the NIH-sponsored T2D-GENES (Type 2 Diabetes Genetic Exploration by Next-generation sequencing in multi-Ethnic Samples) study.

The scientists' approach also will enable them to determine whether there are T2D risk variants that are unique to an ancestry group.

An initial analysis of the data on 3,500 African-American, East Asian and South Asian individuals identified about 1.6 million single nucleotide variants (SNVs), 71.5% of which were previously unknown.

"Only about 89,000, or 5.6%, of the 1.6 million variants are present in all three groups," said Dr. Teslovich.

About 35.4% of these SNVs were unique to African-American, while 35.4% and 30.6% occurred only in East Asian and South Asian samples, respectively. Dr. Teslovich pointed out that their analysis is too preliminary to state that these population-specific variants are associated with T2D and contribute to disease risk in a single population.

By the end of 2012, the researchers will complete sequencing, which began in 2011, Dr. Teslovich said. "A total of about 5,300 individuals, half with type 2 diabetes and half controls, have been sequenced thus far," she added.

By comparing the DNA of individuals with T2D and controls, the scientists hope to isolate genes or variants that increase or reduce an individual's predisposition for developing the disease, said Dr. Teslovich.

"The unique study design will yield a catalog of variation, including alleles that are common in the population as well as those that are observed in only a small number of individuals. We'll examine each of the variants to determine which may affect an individual's risk of developing type 2 diabetes," said Dr. Teslovich.

"In addition to exome-wide analysis, we are focusing detailed mapping efforts in regions of diabetes-related traits such as fasting glucose and insulin," she added. "We anticipate that analysis of the full dataset will lead to identification of causal genes and variants."

In addition to SNVs, the researchers are searching for insertions or deletions of DNA sequence within genes as well as incorrect numbers of whole genes. The latter is referred to as copy number variations.

All the DNA sequence data and medical information will be deposited into dbGaP, the repository for genotype-phenotype relationships sponsored by the National Center for Biotechnology Information of NIH. T2D-GENES is funded by NIH's National Institute of Diabetes and Digestive and Kidney Diseases and the National Human Genome Research Institute.

A total of 75 scientists at 27 universities and other institutions are conducting T2D-GENES studies. The principal investigators of T2D-GENES are Michael Boehnke, Ph.D., University of Michigan; Mark McCarthy, M.D., University of Oxford; David Altshuler, M.D., Ph.D., Broad Institute of Harvard and MIT; Ravindranath Duggirala, Ph.D., Texas Biomedical Research Institute; and Craig Hanis Ph.D., University of Texas at Houston. Dr. McCarthy and Nancy Cox, Ph.D., University of Chicago, lead the analysis committee for this project.


Story Source:

The above story is based on materials provided by American Society of Human Genetics. Note: Materials may be edited for content and length.


Cite This Page:

American Society of Human Genetics. "Novel type 2 diabetes genetic study involves five major ancestry groups." ScienceDaily. ScienceDaily, 8 November 2012. <www.sciencedaily.com/releases/2012/11/121108205846.htm>.
American Society of Human Genetics. (2012, November 8). Novel type 2 diabetes genetic study involves five major ancestry groups. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2012/11/121108205846.htm
American Society of Human Genetics. "Novel type 2 diabetes genetic study involves five major ancestry groups." ScienceDaily. www.sciencedaily.com/releases/2012/11/121108205846.htm (accessed September 20, 2014).

Share This



More Health & Medicine News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
How The 'Angelina Jolie Effect' Increased Cancer Screenings

How The 'Angelina Jolie Effect' Increased Cancer Screenings

Newsy (Sep. 19, 2014) Angelina's Jolie's decision to undergo a preventative mastectomy in 2013 inspired many women to seek early screenings for the disease. Video provided by Newsy
Powered by NewsLook.com
The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
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:
from the past week

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