Next-Generation Noninvasive Diagnostic Technology Shown to Accurately Detect Fetal Down Syndrome in First Trimester of Pregnancy

Sequenom, Inc. (NASDAQ:SQNM) announced new data from a collaborative project with The Chinese University of Hong Kong, published this week in the Early Edition of the Proceedings of the National Academy of Sciences, that demonstrate its innovative, next-generation, noninvasive prenatal diagnostic technology accurately quantified maternal plasma DNA sequences for fetal Trisomy 21, or Down syndrome, based on samples taken from women in the first and second trimesters of pregnancy. These data are the first to suggest that this future approach, based on massively parallel genomic DNA sequencing, can be effective in women who had not previously undergone invasive procedures.

This study used massively parallel genomic sequencing to quantify maternal plasma DNA sequences for the noninvasive prenatal detection of Down syndrome, assessing samples from 28 women in the first and second trimesters of pregnancy. All 14 Down syndrome fetuses and normal fetuses were correctly identified at these early stages.

"Current invasive methods for diagnosing Down syndrome in pregnancy have documented risks associated with such procedures. Our new study using massively parallel genomic DNA sequencing represents a ‘next-generation’ technology for noninvasive, safe testing of Down syndrome. This is the first study to show that this approach can be used for the detection of Down syndrome in both the first and second trimesters, based on a rigorously controlled clinical cohort in which the pregnant women with fetuses affected by Trisomy 21 and those with normal fetuses were matched in gestational age, and in which most of the studied subjects had not previously undergone an invasive procedure. The latter point is important as it shows that the method would truly work in the noninvasive prenatal diagnostic scenario. This study also employs a novel data analysis algorithm which has achieved an unprecedented clear separation of the Trisomy and normal samples,” stated Dennis Lo, M.D., Ph.D., co-author of the study, and Li Ka Shing, Professor of Medicine at The Chinese University of Hong Kong. "While this new approach is several years away as a commercially viable test, we believe that massively parallel genomic sequencing of DNA in maternal plasma may offer a complementary approach to the RNA SNP allelic ratio approach that we reported last year for Trisomy 21 detection. The two approaches have performance and cost profiles which would potentially be synergistic to one another.”

Sequenom licensed the exclusive rights to the massively parallel genomic DNA sequencing technology featured in this study from The Chinese University of Hong Kong in September 2008.

"Screening tests currently available for early detection of Down syndrome and other chromosomal disorders are associated with a relatively high rate of inaccuracy, which can result in an overlooked abnormality or, in the case of false positive results, unnecessary invasive and risky procedures,” stated Harry Stylli, Ph.D., President and Chief Executive Officer of Sequenom. "Systems to support DNA sequencing like massively parallel genomic sequencing or shotgun sequencing are currently limited to the academic setting due to scalability limitations and high cost, therefore practical applications are several years from commercialization. We find the data reported by Dr. Lo and associates to be very compelling and, while we continue to evaluate other promising approaches, Sequenom licensed this technology several months ago because we believe massively parallel genomic sequencing is a promising approach to prenatal diagnostics that may offer a future extension to our SEQureDx™ prenatal diagnostics franchise. Even though this technology is years away from the clinic, we expect that our current RNA SNP allelic ratio technology – which is the basis for the Down syndrome test we expect to launch in June 2009 – will represent a major step forward in maternal and fetal testing.”

Current screening technology for Down syndrome includes serum marker analysis, such as the quad screen and first trimester combined screening that employs both serum marker testing and nuchal translucency. These approaches have detection or sensitivity rates of 80% and 85% respectively, which means between 15% and 20% of all Down syndrome-affected pregnancies will not be identified as needing further evaluation. In addition, these approaches also have false positive rates between 5% and 10%, resulting in hundreds of thousands of unnecessary, highly invasive CVS or amniocentesis procedures. These invasive procedures, which are used to determine whether the fetus has Down syndrome, carry a risk of miscarriage in the range of one-in-100 to one-in-300.

The study, entitled "Noninvasive prenatal diagnosis of fetal chromosomal aneuploidy by massively parallel genomic sequencing of DNA in maternal plasma” by Chiu et. al., is available online in this week’s Early Edition of PNAS at www.PNAS.org.

Sequenom's Proprietary Noninvasive Prenatal Diagnostics

Sequenom's commercial opportunities in prenatal diagnostics are built upon its SEQureDx technologies and are enabled by the pioneering inventions and associated intellectual property rights that it has exclusively licensed from Isis Innovation Ltd., the technology transfer company of the University of Oxford, as well as The Chinese University of Hong Kong. Sequenom's portfolio of noninvasive prenatal diagnostic patent rights and patent applications is platform-independent, includes genetic-analysis methods using circulating cell-free fetal nucleic acids from maternal serum, plasma or whole blood, and also includes a portfolio of methylation and nucleic-acid markers. Sequenom holds exclusive rights in territories including the United States, Europe, Australia, Canada, Japan and Hong Kong. Sequenom is actively expanding its intellectual property position with new technology and new territories. Because Sequenom's license rights are platform-independent, the rights provide exclusivity (with the narrow exception in Europe for RT-PCR-based Rhesus D tests) for development and commercialization of noninvasive prenatal screens and tests on any platform and are not limited to the Company's MassARRAY^® platform.

About SEQureDx Technology

Sequenom's SEQureDx Technology is a novel approach to genetic screening. Unlike current standards of harvesting placental tissue cells as is required for chorionic villus, or entering the uterus to sample the amniotic fluid surrounding the baby as is performed with amniocentesis, SEQureDx Technology extracts Fetal Nucleic Acid material safely and comfortably from a simple blood specimen collected from the mother to determine the genetic status of the fetus. This breakthrough suggests that effective screening may be accomplished in the future without the risks associated with disturbing the amniotic fluid that surrounds the baby in the uterus. In December 2007, the Company, through a laboratory partner, introduced a laboratory-developed RHD genotyping test using RT-PCR in the United States.

Sequenom continues to make substantial progress with its noninvasive Trisomy 21 test based on multiple RNA fetal markers, including the PLAC4 gene as previously published by Dr. Dennis Lo. Recently, Sequenom announced initiation of a 16-month RNA-based Noninvasive Aneuploidy (RNA) study to evaluate its Trisomy 21 technology performance in up to 10,000 women with high-prevalence pregnancies within the first trimester. Led by Drs. Jacob Canick, Ph.D. and Glenn Palomaki from Women & Infants Hospital at Alpert Medical School of Brown University in Providence, Rhode Island, the study’s primary goal is to document the performance (clinical sensitivity and false-positive rate) of Sequenom’s Trisomy 21 technology that uses fetal RNA in maternal plasma to identify Down syndrome in early pregnancy. The study is expected to be completed post-launch of the Trisomy 21 test.

About Down Syndrome

Down syndrome is a chromosomal abnormality characterized by the presence of an extra copy of genetic material on the 21st chromosome, either in whole (Trisomy 21) or in part (such as due to translocations). The effects of the extra copy vary greatly among people. In 2007, the American College of Obstetricians and Gynecologists (ACOG) endorsed guidelines that offer risk assessment to all pregnancies for fetal chromosomal abnormalities, including Down syndrome. The ACOG recommendation includes screening before the 20th week of pregnancy using a less-invasive screening option that includes ultrasound in conjunction with the measurement of certain blood hormones. It is estimated that approximately 70%, or 2.8 million, women undergo Down syndrome screening in the United States each year.

About Sequenom

Sequenom is committed to providing the best genetic analysis products that translate the results of genomic science into solutions for noninvasive prenatal diagnostics, biomedical research, translational research and molecular medicine applications. The Company's proprietary MassARRAY system is a high-performance (in speed, accuracy and cost efficiency) nucleic acid analysis platform that quantitatively and precisely measures genetic target material and variations. The Company has exclusively licensed intellectual property rights for the development and commercialization of noninvasive prenatal genetic tests for use with the MassARRAY system and other platforms. For more information on Sequenom, please visit the Company's Web site at www.sequenom.com.

Sequenom^®, MassARRAY^® and SEQureDx™ are trademarks of Sequenom, Inc.

About The Chinese University of Hong Kong

Founded in 1963, The Chinese University of Hong Kong (CUHK) is a forward looking comprehensive research university with a global vision and a mission to combine tradition with modernity, and to bring together China and the West. CUHK teachers and students hail from all corners of the world. In 2007, CUHK had more than 6,100 staff members, approximately 10,000 undergraduate and 3,300 research postgraduate students. Of these students, some 2,500 are from 45 countries and regions outside Hong Kong. The University received research funding of close to HK$400 million in the 2006/07 academic year from various local and overseas sources. Four research areas led by CUHK staff have been selected as four of only ten Areas of Excellence funded by the University Grants Committee. CUHK research centers have close collaboration with mainland China and overseas institutions. Many research products have been put into practical use through technology transfer and spin-off companies. Technology transfer at CUHK is handled by the Technology Licensing Office headed by Ms. Alice Ngan.

Forward-Looking Statements

Except for the historical information contained herein, the matters set forth in this press release, including statements regarding the future of, development, commercialization and related timelines, and expectations regarding massively parallel genomic DNA sequencing approaches to prenatal diagnostics including testing of Down syndrome, other potential DNA sequencing approaches, the Company’s expectations regarding its RNA SNP allelic ratio approach for prenatal diagnostics including its potential synergies with the massively parallel genomic DNA sequencing approach, its expected launch in June 2009 and its impact on maternal and fetal testing, the Company’s commercial opportunities in prenatal diagnostics, effective prenatal screening in the future, and the goals and expected completion of the Company’s RNA-based Noninvasive Aneuploidy study, are forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially, including the risks and uncertainties associated with the Company's operating performance, demand for and market acceptance of the Company's products, services, and technologies, new technology and product development and commercialization particularly for new technologies such as molecular diagnostics, and particularly noninvasive prenatal diagnostics, reliance upon the collaborative efforts of other parties, research and development progress, competition, intellectual property protection, government regulation, obtaining or maintaining regulatory approvals, and other risks detailed from time to time in the Company's SEC (U.S. Securities and Exchange Commission) filings, including the Company's Annual Report on Form 10-K for the year ended December 31, 2007 and other documents subsequently filed with or furnished to the SEC. These forward-looking statements are based on current information that may change and you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. All forward-looking statements are qualified in their entirety by this cautionary statement, and the Company undertakes no obligation to revise or update any forward-looking statement to reflect events or circumstances after the issuance of this press release.