By Bailey Mulford and Rachel Lanaghen Down’s Syndrome By Bailey Mulford and Rachel Lanaghen

OVERVIEW Down’s syndrome, named after Dr. John Langdon Down, is a chromosomal disorder. It is caused due to trisomy, the presence of an extra copy, of the 21st chromosome.

PHYSICAL SYMPTOMS Typically have a very round face “Almond-shaped” eyes Brushfield spots (white spots on the iris) Flat bridge of the nose Protruding tongue due to a small oral cavity and enlarged tongue) Shorter neck Congenital heart defects Large space between the big toe and second toe Muscle hypotonia (poor muscle tone) Most exhibit mild to moderate mental retardation

INHERITANCE Down’s is inherited one of three ways… Non-disjunction (95%) – during meiosis, a gamete ends up with 24 chromosomes rather than the usual 23 Translocation (3-4%) – where one of the parents has chromosome 21 attached to another chromosome, usually chromosome 14 Mitotic Errors (<3%) – in early development of the fetus, the chromosome 21 pair fails to separate in anaphase

STATISTICS Down’s Syndrome is estimated to be anywhere from 1 in 800 to 1 in 1000 As of 2006, the estimate was 1 in 733 live births Maternal age has a strong influence on if the baby has a third copy of chromosome 21. As shown in the graph to the right, as the age of the mother increases, the instances with Down’s increases accordingly.

PROGNOSIS AND TREATMENT Down’s Syndrome can be detected through a number of prenatal screening techniques including… Amniocentesis- sample of amniotic fluid Chronice villus sampling (CVS) Percutaneous umbilical blood sampling (PUBS) Triple screen- measures protein and hormone levels Quad screen- measures protein and hormone levels AFP/free beta screen- measures protein levels PAPPA screen- uses ultrasound that measures protein levels These tests are 90-95% accurate with 2-5% false positives. At present, there are no cures or treatment for Down’s Syndrome. However, many of the symptoms such as congenital heart failure may be treated with various medications.

LIFE EXPECTANCY Individuals with Down’s Syndrome have a slightly higher morbidity rate due to impaired immune responses, increase in congenital heart disease, and airway obstructions. The estimated lifespan is 49 years, which is a dramatic increase from the 24 years of age in 1980. 75% die in embryonic or fetal life 15% die within the first year after their birth 50% live past 50 years of age

LIVING WITH DOWN’S SYNDROME From the early 20th century through the 1960s many people with down syndrome were put into institutions, largely excluded from the rest of society. Now that scientists and doctors better understand this disorder a more humane policy of inclusion has been initiated.

Inclusion Inclusion is a strategy that works at meeting the needs of people with down syndrome as much as possible in public education and developmental institutions. There are many academic and social benefits for both students with the disorder and students without it when they are given the opportunity to learn and grow together. New Friendships Non-disabled students are more appreciative of differences Students with disabilities are more motivated when they are pushed to their potential like any other person

LIVING WITH DOWN SYNDROME Today… Most children with down syndrome go to public school and participate in many of the same activities as non-disabled students (although some do perform better in specialized programs) Many go to college Many live in semi-independent housing and hold jobs The National Down Syndrome Society is trying to expand post secondary opportunities by developing a model school/program especially fitted for people with down syndrome. Their fertility is significantly decreased (only 3 recorded fathers in history) and there is no evidence to support that this a hereditary disorder. Most people with this disorder live happy, rewarding lives. Gradually mainstream society is beginning to understand the unique and contributions and talents they have.

Resources Local support groups and instructional programs for new parents and relatives can be found through these national organizations: National Down Syndrome Congress www.ndsscenter.org National Association for Down Syndrome www.nads.org National Down Syndrome Society www.ndss.org Band of Angels Foundation www.bandofangels.com

WORKS CITED “Down’s Syndrome”, Wikipedia, http://en.wikipedia.org/wiki/Down%27s_sydrome “Down’s Syndrome”, BioZone, pg.203 “Down Syndrome” eMedicine http://emedicine.com/ped/topic615.htm