Affymetrix Technology Used to Discover Common Genetic Variant Associated with Height Variation.

SANTA CLARA, Calif. -- Affymetrix Inc. (Nasdaq:AFFX) today announced that its microarray technology was used to discover a common genetic variant associated with adult and childhood height in the general population. A team of scientists used the Affymetrix technology to perform a large-scale whole-genome association study that analyzed the genetic information of approximately 5,000 individuals. The results of the project were published in the October 2007, issue of Nature Genetics.

Previous studies on height variation in the general population lacked the overall statistical power to detect true genetic associations. Through a combination of the Affymetrix GeneChip([R]) 500K Arrays and large sample cohorts, a team of researchers from the Broad Institute of Harvard and MIT, Children's Hospital Boston, the University of Oxford and Peninsula Medical School of Exeter were able to determine that a variation in the HMGA2 gene has a strong correlation with a person's height.

"To our knowledge, these results represent the first reproducible association of a common variant with human stature and suggest that by analyzing data from many thousands of individuals, it will now finally be possible to dissect the genetics of this highly heritable polygenetic trait," said Timothy M. Frayling, Ph.D., associate professor, Peninsula Medical School. "Insights gained from this study should lead to important discoveries on other complex traits and complex diseases."

The team was able to identify the genetic variant using data made available from two recent whole-genome association studies on type 2 diabetes across approximately 5,000 individuals. To replicate this finding in additional population-based studies, the researchers analyzed the specific variant across another 29,000 individuals and combined the information gained from previous whole-genome studies. This approach improved the overall genetic power of the study and enabled the team to conclude that it is more likely for a taller person to possess a certain variation in the HMGA2 gene.

"Researchers around the world are using the Affymetrix whole-genome SNP panels to identify the genetic causes of complex diseases and quantitative traits, such as human height," said Mindy Lee-Olsen, senior director of academic marketing at Affymetrix. "Through a combination of the latest advances in Affymetrix technology and availability of large cohort sample data, scientists are now able to increase the overall genetic power of their experiments to gain a better understanding of human life."

About Affymetrix

Affymetrix GeneChip([R]) microarray technology is the industry-standard tool for analyzing complex genetic information. After inventing microarray technology in the late 1980s, Affymetrix scientists have been dedicated to developing innovative products that provide researchers with a more complete view of the genome. These products continue to accelerate genetic research and enable scientists to develop diagnostics and tailor treatments for individual patients by identifying and measuring the genetic information associated with complex diseases.

Today, Affymetrix technology is used by the world's top pharmaceutical, diagnostic and biotechnology companies, as well as leading academic, government and not-for-profit research institutes. More than 1,600 systems have been shipped around the world and more than 9,500 peer-reviewed papers have been published using the technology.

Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in Sacramento, Calif., and Singapore. The company has about 1,100 employees worldwide and maintains sales and distribution operations across Europe and Asia. For more information about Affymetrix, please visit the company's website at www.affymetrix.com.

Forward-looking Statements

All statements in this press release that are not historical are "forward-looking statements" within the meaning of Section 21E of the Securities Exchange Act as amended, including statements regarding Affymetrix' "expectations," "beliefs," "hopes," "intentions," "strategies" or the like. Such statements are subject to risks and uncertainties that could cause actual results to differ materially for Affymetrix from those projected, including, but not limited to: risks and uncertainties associated with the use of the Affymetrix technology and uncertainties related to the implications of the findings of the study discussed in this press release; risks of the company's ability to achieve and sustain higher levels of revenue, higher gross margins and reduced operating expenses; uncertainties relating to technological approaches, manufacturing and product development; personnel retention; uncertainties related to cost and pricing of Affymetrix products; dependence on collaborative partners; uncertainties relating to sole-source suppliers; uncertainties relating to FDA and other regulatory approvals; competition; risks relating to intellectual property of others and the uncertainties of patent protection and litigation. These and other risk factors are discussed in Affymetrix' Form 10-K for the year ended December 31, 2006, and other SEC reports, including its Quarterly Reports on Form 10-Q for subsequent quarterly periods. Affymetrix expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in Affymetrix' expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.

NOTE: Affymetrix, the Affymetrix logo and GeneChip([R]) are registered trademarks owned or used by Affymetrix Inc.