Ultrasensitive DNA Screening for Down Syndrome Offers Potential for Early Detection

MedicalResearch.com Interview with:

Zhiyong Zhang PhD Key Laboratory for the Physics and Chemistry of Nanodevices and  Department of Electronics Peking University Beijing China

Prof. Zhang

Zhiyong Zhang PhD
Key Laboratory for the Physics and Chemistry of Nanodevices
Department of Electronics
Peking University
Beijing China

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Down syndrome is caused by the presence of an extra 21st chromosome within the genome and is the most common birth defect (occurring in approximately 1 in 800 births). In the absence of a multiplexed quantitative diagnostic device, pregnant women have been examined with the ultrasound and the indirect biochemical markers (Alpha-fetoprotein, chorionic gonadotropin and free estriol) which are accompanied with a high misdiagnosis rate. And the diagnostic test (such as amniocentesis) following the wrong screening test results will bring harm to both the pregnant women and the fetuses.

Through PCR (polymerization chain reaction) amplification of the fetal DNA in the pregnant mother’s peripheral blood and fluorescence read-out, whole-genome sequencing (WGS)-based non-invasive prenatal testing (NIPT) sequences all the genomic DNA segments in parallel and quantitatively compares the percentage of different chromosomes, which increases the sensitivity for prenatal detection of Down syndrome. However, the complex instrumental setups and the resulted high processing cost present challenges for the large-scale application of WGS-based diagnosis at the point of care in the urban and rural areas of developing countries. Hence, beside the costly WGS method, there is an urgent need to develop a cost-effective NIPT biochip with simple instrumental setting, fast detection speed, high sensitivity, and programmable to multiple disease markers.

Taking advantages of we have developed a novel field effect transistor (FET) based biosensor that reveals a fast, ultra-sensitive, highly specific and cost-effective methods and someday can be used to detect fetal Down syndrome in NIPT.  Continue reading

Adults with Down’s Syndrome at High Risk of Alzheimer’s Disease

MedicalResearch.com Interview with:
"A neonate with Down's?" by Sadasiv Swain is licensed under CC BY 2.0Rosalyn Hithersay

LonDowns
Kings College, London 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: In our research group, we have been following a large group of adults with Down syndrome in the UK to track changes with ageing in their health and cognitive function. It has been known for some time now that people with Down syndrome are at high risk for developing dementia due to Alzheimer’s disease. This new study has shown the huge impact that this risk has on mortality for these adults.

We found that dementia is now the likely underlying cause of death in more than 70% of adults with Down syndrome aged over 35 years. This is a much bigger proportion of deaths due to Alzheimer’s disease compared to the general population: in England and Wales only 17.5% of deaths past the age of 65 would be related to dementia of any kind.  Continue reading