Trisomy 21/Down Syndrome

We have developed and are validating a novel approach to screen for Trisomy 21 (Down Syndrome) by assessing chromosomal relative allele frequency using single nucleotide polymorphism (SNP) markers that span chromosome 21, followed by quantitative assessment of relative allele signal strength using pyrosequencing. We believe that using this molecular-based screening method will lead to an effective, rapid, low-cost screening test for detecting Down Syndrome with broad commercial application. While still in the early development stages, results to date are encouraging and conditions are currently being optimized. A provisional patent for this product was filed with US PTO in April 2009.

The risk for aneuploidy increases with a woman's age, regardless of family or medical history. The chromosomes in an older woman's egg are less likely to divide properly, possibly resulting in the egg having an extra or missing
chromosome. The estimated chances for a woman to deliver a child with an aneuploidy condition are as follows:

At age 30 years - 1/385
At age 35 years - 1/179
At age 40 years - 1/63
At age 45 years - 1/19

However, the frequency of aneuploidy in embryos is much higher than the number of babies born with aneuploidy conditions; a pregnancy with aneuploidy is less likely to attach to the uterus (implant) and has a
greater risk for miscarriage. The lack of implantation and the loss rate of aneuploid embryos are believed to be the main reasons why the pregnancy rate in women over 40 is so low. The purpose of genetic diagnosis for aneuploidy is to increase the pregnancy rate and reduce the number of pregnancy losses.