| Every year, one child in every 800 to 1,000 | | | | with the physical and/or developmentally |
| births will be born with a condition known as | | | | delayed characteristics of those born with |
| Down syndrome. Down syndrome is a disorder in | | | | the other two forms of Down syndrome. |
| which the child has extra genetic material. | | | | |
| This extra genetic material causes the baby | | | | Common Physical Traits |
| to develop differently in the womb. This | | | | |
| abnormal development occurs during the early | | | | Babies with Down syndrome are usually |
| stages of cell division, soon after | | | | diagnosed at birth or shortly thereafter. |
| conception. | | | | Because Down syndrome affects a child |
| | | | physically, there will be certain features |
| There is no known reason for Down syndrome or | | | | that an alert doctor or nurse will pick up |
| a cure for it. | | | | on. Most children with the syndrome will have |
| | | | some or all of these traits. |
| The disorder came by its name when an English | | | | |
| physician, John Langdon Down, published a | | | | Among the most common physical |
| description of the characteristics of a | | | | characteristics are: |
| person with the condition in 1886. Since Dr. | | | | |
| Down was the first person to give the | | | | - Low muscle tone |
| syndrome a name, the disorder is known as | | | | |
| Down syndrome. | | | | - Small nose and flat nasal bridge |
| | | | |
| The Common Forms of Downs | | | | - An upward slant to the eyes (almond shaped) |
| | | | |
| There are three distinct forms of Down | | | | - Small skin folds on the inner corner of the |
| syndrome. The most common form is Trisomy 21. | | | | eyes |
| This is when a child has an extra chromosome | | | | |
| 21. | | | | - Tongue large for size of child's mouth |
| | | | |
| Instead of having 46 chromosomes in each cell | | | | - Small, sometimes abnormally shaped ears |
| (23 from the father and 23 from the mother), | | | | |
| he has 47. Ninety-five percent of children | | | | - A single crease across the center of the |
| born with Down syndrome have Trisomy 21. | | | | palm |
| | | | |
| Translocation is another form of Down | | | | - Fifth finger, the pinky, has only one |
| syndrome and makes up 3 to 4% of the | | | | crease instead of two |
| population of people with the disorder. | | | | |
| Translocation occurs when part of chromosome | | | | - Larger than normal space between the large |
| 21 breaks off and attaches to another | | | | and second toe |
| chromosome, changing the genetic makeup. In | | | | |
| this form of Down syndrome, each cell has the | | | | - Joints are hyper flexible, able to extend |
| normal 46 chromosomes, but there is extra | | | | greater than average |
| genetic material from the broken off | | | | |
| chromosome. | | | | These physical traits are characteristic of a |
| | | | baby with Down syndrome, but in order to |
| The third and final form is called Mosaicism, | | | | determine if a child does indeed have the |
| and is the rarest form of Down syndrome, | | | | disorder, a chromosome analysis will need to |
| occurring in only 2% of all cases. Mosaicism | | | | be performed. |
| happens when some of the cells in the forming | | | | |
| embryo have 46 chromosomes, and some have 47. | | | | This is done by taking blood from your baby |
| Thus, the alternating pattern gives it the | | | | and the analysis will be done in a |
| name Mosaicism. | | | | laboratory. Your doctor will notify you of |
| | | | the results. |
| People with Mosaicism may not be as affected | | | | |