Affymetrix Technology Helps Advance Schizophrenia Research.

Three International Studies Use Affymetrix SNP Arrays to Discover Copy Number Variations Linked to Mental Disorder 

SANTA CLARA, Calif. -- Affymetrix Inc. (Nasdaq:AFFX) announced today that researchers around the world have used the Affymetrix Genome-Wide Human SNP Arrays 5.0 and 6.0 to uncover important links between copy number variations (CNVs) and schizophrenia. Researchers from the United States, Europe and Asia published their findings in recent issues of Nature and Nature Genetics.

Schizophrenia is a chronic and disabling disorder that affects 2.4 million Americans alone. Even with the best treatments currently available, most patients do not recover fully.1 About 40 percent of the disease is thought to be inherited, and the other 60 percent sporadically shows up in people whose family history does not include the disease.2 The results of the recent studies could help clinicians develop potential drug targets and enable better diagnoses for more personalized treatments.

The first study was conducted by a team of scientists from the Columbia University Medical Center. They used the Affymetrix SNP Array 5.0 to uncover a clear link between rare de novo copy number variations and sporadic schizophrenia in an African population.3 The team discovered 17 de novo CNVs in patients with schizophrenia and showed that rare de novo CNVs are approximately eight times more likely to appear in sporadic cases with schizophrenia than in unaffected individuals. A number of genes harbored within these detected gains and losses are members of pathways previously associated with neural development and RNA binding and processing.

"This is the first high-resolution, family-based study which examined in a systematic manner whether rare copy number mutations contribute to sporadic schizophrenia," said Maria Karayiorgou, M.D., professor of psychiatry at Columbia University Medical Center. "The Affymetrix technology made it possible for us to discover that de novo copy number mutations account for at least 10 percent of the non-familial cases of this devastating disease. Now that we better understand what brain development pathways are involved with schizophrenia, we can look at better ways of treating it in the future."

The second study was carried out by the International Schizophrenia Consortium (ISC), which consists of researchers from the U.S., Europe and Australia.4 A third project was performed by the SGENE collaboration, a group of 18 institutions across Europe, the U.S. and China.5 The two groups used the Affymetrix SNP Array 6.0 to detect genetic deletions associated with schizophrenia in the same three locations: chromosomes 1, 15 and 22. The SGENE collaboration located an additional deletion on chromosome 15, and the ISC found that people with the disease are generally more likely to carry rare chromosomal structure changes than those without the disease.

"Identifying these genetic deletions provides us with rich clues to follow up in future research on schizophrenia," said Pamela Sklar, M.D., Ph.D., associate director, Psychiatric and Neurodevelopmental Genetics Unit in the Center for Human Genetic Research at Massachusetts General Hospital, director of genetics, Stanley Center for Psychiatric Research at the Broad Institute and a member of the ISC. "Recent advances in high-quality genotyping, such as the newest chip technologies from Affymetrix, enabled us to determine the importance of copy number variations through true genome-wide surveys."

"The Affymetrix SNP Array 6.0 enables researchers to perform the most powerful whole-genome association and copy number studies ever by genotyping more markers across more individuals at a lower cost per sample," said Kevin King, president of Affymetrix. "Scientists around the world are using this power to discover rare genetic variations associated with complex diseases. These three recent schizophrenia discoveries are great examples of research breakthroughs that should bring us closer to a day when we can diagnose, treat and potentially cure this debilitating disorder."

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 1,700 systems have been shipped around the world and more than 13,000 peer-reviewed papers have been published using the technology.

Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in Sacramento, Calif., Cleveland, Ohio, 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 relating to commercial success of the agreements with Columbia University Medical Center, the ISC and SGENE 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 related to technological approaches, manufacturing and product development; personnel retention; uncertainties related to cost and pricing of Affymetrix products; dependence on collaborative partners; uncertainties related to sole-source suppliers; risks associated with past and future acquisitions; 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, 2007, 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.

1 http://www.nih.gov/about/researchresultsforthepublic/Schizophrenia.pdf

2 http://cumc.columbia.edu/news/press_releases/gene-mutation- schizophrenia.html (Due to its length, this URL may need to be copied/pasted into your Internet browser's address field. Remove the extra space if one exists.)

3 Xu, B. et al. Strong Association of de novo copy number mutations with sporadic schizophrenia, Nature Genetics, 2008 Jul;40(7):880-5.

4 International Schizophrenia Consortium, Rare chromosomal deletions and duplications increase risk of schizophrenia, Nature, doi: 10.1038/nature07239 (2008)

5 Stefansson, H. et al., Large recurrent microdeletions associated with schizophrenia, Nature, doi: 10.1038/nature07229