Down syndrome is a genetic abnormality that occurs when you rise to a chromosome ( chromosome 21 ) in the development of a sperm or an egg cell . When the sperm and the ' oocyte give birth to a zygote , the two gene pools are joined by determining the presence of three copies of chromosome 21 instead of due1 . With each cell division , this extra copy of chromosome 21 is found in every cell . This is the condition which is defined as " Trisomy 21 " . Down syndrome is the most frequent among the identified genetic abnormalities . It can cause developmental delays intellectual and physical.
• Approssimativamente dal 60 al 70% delle donne effettuano un test prenatale2
• La maggiorparte dei bambini con sindrome di Down sono nati da donne under 353
• On average, Down syndrome occurs in one in every 691 children born vivi4
• There are about 6 million people in the world with Down Syndrome5
- "American Pregnancy Association." American Pregnancy Association. American Pregnancy Association, n.d. Web. 12 Oct. 2012. www.americanpregnancy.org/main/statistics.html.
- Frost and Sullivan, Strategic Analysis of the U.S. Prenatal Testing Market, N940-55, 2011 6. "Surprising Facts about Birth in the United States." BabyCenter. BabyCenter, L.L.C., Aug. 2011. Web. 12 Oct. 2012.
- California. Department of Public Health. Genetic Disease Screening Program. The California Prenatal Screening Program Provider Handbook. N.p.: n.p., n.d. Web. 12 Oct. 2012. http://www.cdph.ca.gov/programs/pns/Documents/Provider%20Handbook%20%202009%20WEB.pdf.
- "Facts About Down Syndrome." National Association for Down Syndrome. National Association for Down Syndrome, n.d. Web. 12 Oct. 2012. www.nads.org/pages_new/facts.html.
- Steenhuysen, Julie. "Down Syndrome May Hold Key to New Alzheimer's Treatments."Reuters. Thomson Reuters, 25 Sept. 2012. Web. 01 Oct. 2012. www.reuters.com/article/2012/09/25/us-alzheimers-downsyndrome-idUSBRE88O11W20120925.