1. Down Syndrome is also referred to as Trisomy 21. It is caused by an extra 21st chromosome.
2. It is named after John Langdon Down, a British physician who described the syndrome in 1866.
3. Life expectancy for someone with Down Syndrome has increased from 12 years (in 1912) to 60 years. *In March 2012, the Guiness Book of World Records website listed Joyce Greenman, now 87, of London, who was born on 3/14/1925, as the oldest living person with Down Syndrome.
4. 1 in 691 babies, overall, are born with Down Syndrome (0.12%)
<1 in 1000 in women under the age of 30
1 in 400 for women between the ages of 35-40
1 in 110 for women over 40
1 in 25 for women over 45
5. 88% of cases arise from the mother's chromosome 21; 8% arise for the father's chromosome 21; 2% from 'mitotic errors after fusion.'
6. Translocation Down Syndrome occur in 4-5%.
7. 80% of Down Syndrome children are born to women under the age of 35 in the U.S.
8. 40-50% of children with Down Syndrome have cogenital heart defects in the U.S.
9. Having Down Syndrome increases the risk of Leukemia 10-15% in the U.S.
10. 100% of people with Down Syndrome will develop physiological signs of Alzheimer's after the age of 35 in the U.S.
11. In the U.S., it is referred to as "Down Syndrome." In the U.K., it is referred to as "Downs Syndrome."
12. 66-89% of individuals with Down Syndrome have some level of hearing loss in at least one ear.
13. The risk of pneumonia is 62 times higher than in non-Down Syndrome individuals.
14. Seizures occur in 3-13% of individuals with Down Syndrome.
15. There are more than 400,000 people living with Down Syndrome in the U.S.