Corporate Banner
Satellite Banner
Scientific Community
Become a Member | Sign in
Home>News>This Article

AD GWAS in African Americans Confirms, Reshuffles AlzGene List

Published: Monday, April 15, 2013
Last Updated: Monday, April 15, 2013
Bookmark and Share
African Americans carrying a variant in a cholesterol-processing gene have double the risk for Alzheimer’s than non-carriers.

This gene, for a membrane transporter protein called ABCA7, is the greatest difference between African American and Caucasian Alzheimer’s risk to emerge from the largest genomewide association study (GWAS) for AD performed in African Americans to date. The study appears April 10 in the Journal of the American Medical Association. In African Americans, ABCA7 variation is the strongest genetic risk factor for AD outside of the ApoE4 allele. Other than that, the genes involved in African American AD risk paralleled those in whites, reported the study authors representing the Alzheimer's Disease Genetics Consortium.

Led by senior author Richard Mayeux at Columbia University in New York City, the researchers examined single-nucleotide polymorphisms from nearly 2,000 people with late-onset Alzheimer’s, and almost 4,000 control participants. The group collected all the data it could get from African Americans seen at more than 20 study centers, said first author Christiane Reitz, also at Columbia.

While many of the previously reported GWAS data come from people of European and European American ancestry, Reitz noted that it is important to investigate whether those genetic findings extend to people beyond that white slice of humanity. A GWAS in Hispanics is ongoing.

Several of the genes the current study picked out in African Americans matched those found in GWAS with white people. ApoE4 was the strongest risk factor; a single copy more than doubled risk of Alzheimer’s with an odds ratio of 2.31 in this report. “Replicating an association for the same alleles in different ethnic groups strengthens the case for these variants being important in increasing disease susceptibility,” commented Robert Nussbaum of the University of California, San Francisco, in an editorial accompanying the publication.

After ApoE, ABCA7 was second on the hit list. ABCA7 variants had been reported to increase risk in white people, but ABCA7 was in the middle of the pack among genes linked to AD, most of which boost risk by an average of 10-20 percent, Reitz said (Hollingworth et al., 2011). ABCA7 currently ranks fourth on the AlzGene Top 10. In the new study’s African American population, an ABCA7 variant increased one’s chances of AD by almost double, with an odds ratio of 1.79.

This kind of race-based difference is not uncommon, Reitz noted. She suspects that the ABCA7 polymorphisms found in Caucasians point to specific functional mutations different from those carried by African Americans, but the researchers have not yet sequenced the gene to check. It is also possible that the genetic background of each race, as well as environmental factors, conspire with ABCA7 variants to produce a higher risk in African American carriers than in whites.

Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More than 5,200+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

AD GWAS in African Americans Confirms, Reshuffles AlzGene List
African Americans carrying a variant in a cholesterol-processing gene have double the risk for Alzheimer’s than non-carriers.
Thursday, April 11, 2013
Scientific News
Unravelling the Role of Key Genes and DNA Methylation in Blood Cell Malignancies
Researchers from the University of Nebraska Medical Center have demonstrated the role of Dnmt3a in safeguarding normal haematopoiesis.
Genes Help Track Odd Migrations of Zika Mosquitoes
Study shows that mosquitoes carrying Zika virus or Dengue fever a genetically distinct around the world.
Editing Gene Mutations in Anemia
Researchers successfully use a new gene editing strategy to correct mutations that cause a form of anemia.
Lab-on-a-Chip to Help Detect Cancer
In this podcast, we speak to Gustavo Stolovitsky to learn about his career and the work he is doing at IBM Research.
Rare Immunodeficiency Yields Unexpected Insights
Scientists uncover previously unknown gene mutation revealing the role of a key molecule involved in immune cell development.
Driving Mosquito Evolution to Fight Malaria
Researchers propose insect repellent in conjunction with insecticides to extend current insecticide lifetime.
Tumor Markers Reveal Lethality Of Bladder Cancers
Researchers found that detection of certain tumor cells in early stage cancers helps identify high-risk cancers.
Gene Editing Corrects Sickle Cell Mutation
Researchers demonstrate a potential pathway to developing gene-editing treatments for sickle cell disease.
ALS Study Reveals Role of RNA-Binding Proteins
The findings are a significant step forward in validating RNA-based therapy as a treatment for ALS.
Observing Direct Inheritance of Gene-Silencing RNA
Research has allowed for the observation of double-stranded RNA molecule being passed from parent to offspring in roundworms.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,200+ scientific videos