Down syndrome is common in the United States. According to Gould and Dyer (2011), Down syndrome is an example of trisomy because there are three chromosomes instead of two at position 21. This means that people with Down syndrome have a total of 47 chromosomes instead of the original 46. The body is marked by the effects of trisomy 21. The effects of trisomy 21 can lead to defects in physical and mental development. Down syndrome was initially also called monogolism, but is now more commonly known as Down syndrome. The risk of giving birth to a child with Down syndrome increases with maternal age. A 30-year-old woman has an approximately 1 in 1000 risk of having a baby with Down syndrome, a 35-year-old woman has a 1 in 500 risk, and at 40 there is a 1 in 100 risk (Gould & Dyer , 2011). It is not known whether this is due to damage to the oocytes resulting from degenerative factors with aging or from environmental substances. In some cases this must also have been due to paternal origin. This disorder can be detected by a triple positive test on the mother's blood followed by an amniocentesis (Gould & Dyer, 2011). According to Gould and Dyer (2011), the characteristics of people with Down syndrome are typically a small head with a flat facial profile, the eyes are slanted and the irises contain Brushfield spots, the mouth tends to open by hand, the large tongue and the arched palate. The person may also have a single, small palmar crease, hypotonic muscles, loose joints, cervical abnormalities, short stature, delayed developmental stages, delayed or incomplete sexual development, and children are at risk for other problems such as vision problems, hearing problems , digestive tract obstructions, celiac disease... half the paper... that's done, then the nurse will follow up with the patient for any doubts or questions he may have. Silencing chromosome 21 allows older women to have children without the possible risk of having a child with Down syndrome. Silencing of chromosome 21 is an important event for nurses, as it helps increase the lifespan of children and allows people to have children regardless of age. Works Cited Gould, B. E. & Dyer, R. M. (2011). Pathophysiology for the Health Professions (4th Ed.). (pp. 150-154). St. Louis: Saunders. Jiang, J., Jing, Y., Cost, G., Chiang, J., Kolpa, H., Cotton, A., Carone, D., Carone, B., Shivak, D. , Guschin, D., Pearl, J., Rebar, E., Byron, M., Gregory, P., Brown, C., Urnov, F., Hall, L., & Lawrence, J. (2013). Translation of dosage compensation in trisomy 21. Nature, 500, 296-300. doi: 10.1038/nature12394