| Every year, one child in every 800 to 1,000 | | | | 3 to 4% of the population of people with the |
| births will be born with a condition known as | | | | disorder. Translocation occurs when part of |
| Down syndrome. Down syndrome is a disorder in | | | | chromosome 21 breaks off and attaches to |
| which the child has extra genetic material. | | | | another chromosome, changing the genetic |
| This extra genetic material causes the baby | | | | makeup. In this form of Down syndrome, each |
| to develop differently in the womb. This | | | | cell has the normal 46 chromosomes, but there |
| abnormal development occurs during the early | | | | is extra genetic material from the broken off |
| stages of cell division, soon after | | | | chromosome.The third and final form is called |
| conception.There is no known reason for Down | | | | Mosaicism, and is the rarest form of Down |
| syndrome or a cure for it.The disorder came | | | | syndrome, occurring in only 2% of all cases. |
| by its name when an English physician, John | | | | Mosaicism happens when some of the cells in |
| Langdon Down, published a description of the | | | | the forming embryo have 46 chromosomes, and |
| characteristics of a person with the | | | | some have 47. Thus, the alternating pattern |
| condition in 1886. Since Dr. Down was the | | | | gives it the name Mosaicism.People with |
| first person to give the syndrome a name, the | | | | Mosaicism may not be as affected with the |
| disorder is known as Down syndrome.The Common | | | | physical and/or developmentally delayed |
| Forms of DownsThere are three distinct forms | | | | characteristics of those born with the other |
| of Down syndrome. The most common form is | | | | two forms of Down syndrome.Common Physical |
| Trisomy 21. This is when a child has an extra | | | | TraitsBabies with Down syndrome are usually |
| chromosome 21.Instead of having 46 | | | | diagnosed at birth or shortly thereafter. |
| chromosomes in each cell (23 from the father | | | | Because Down syndrome affects a child |
| and 23 from the mother), he has 47. | | | | physically, there will be certain features |
| Ninety-five percent of children born with | | | | that an alert doctor or nurse will pick up |
| Down syndrome have Trisomy 21.Translocation | | | | on. Most children with the syndrome will have |
| is another form of Down syndrome and makes up | | | | some or all of these traits. |