by: Jennifer Alvarado p-4
What is Down Syndrome?
1959- Dr. Jerome Lejeune, a French geneticist, discovered that Down Syndrome was the result of a chromosomal abnormality. He found that people with Down had 47 chromosomes instead of 46. Soon it was also discovered, that chromosome 21 held an extra part or complete chromosome. This lead to the creation of the term Trisomy 21. Even now, it is still unknown why this happens.
The three genetic differences that cause Down Syndrome
- The child will have three copies of chromosome 21 instead of two in each of their cells
- Occurs by abnormal cell division during the development of sperm or egg cells.
- Happens more than 90% of the time.
- Happens in rare cases.
- Some cells have an extra copy of chromosome 21.
- This results in a mixture or mosaic of normal and abnormal cells.
- Caused by unusual cell division after fertilization.
- Occurs when a piece of chromosome 21 becomes attached onto another chromosome.
- This happens before or during birth.
- An uncommon form of Down syndrome, occurs only 4% of the time.
- You already have a child with Down Syndrome
- You or your partner are carriers of the genetic translocation for Down syndrome
- You are 35 or older
- Blood test
- Cell-free fetal DNA analysis -the cell-free fetal DNA test checks for fetal DNA circulating in the mother's blood.
- Amniocentesis- A sample of the amniotic fluid surrounding the fetus is withdrawn through a needle inserted into the mother's uterus
- Chorionic villus sampling (CVS)- In CVS, cells are taken from the placenta and used to analyze the fetal chromosomes.
How can you tell if someone has Down Syndrome?
- flattened facial features
- short neck
- upward, slanted eyes
- poor muscle tone
- short fingers
- small but broad hands and feet
- short stature
- irregular shaped ears
- protruding tongue
- excessive flexibility
- Wide separation between first and second toes
- Poor judgment
- Delayed speech and language development
- Short attention span
- Moderate to severe developmental delays
- Cognitive impairment
- Slowed learning
- Thyroid disease
- Heart defects
- Infectious diseases
- Hearing loss
- Premature aging
- Skeletal problems
- Visual problems – crossed-eyes, near or farsightedness, cataracts
- Gastrointestinal abnormalities
- Early-onset Alzheimer’s disease
Is It Heredity?
Down syndrome occurs once in every 800 to 1,000 births, and the majority did not inherit it
- Speech therapy
- Physical therapy
- Regular checkups/screenings
How does Down Syndrome affects the individual?
Around the 1920s, children with Down were expected to survive to the age ten. Now, with recent advancements in clinical treatment, as many as 80% of adults with Down syndrome reach age 60, and many live even longer. Many people are accepting and interacting with individuals with Down Syndrome more :)
down syndrome Organizatons
- National Down Syndrome Society
Blog with more information about what's going on with the Down communityhttp://www.friendshipcircle.org/blog/2013/03/20/42-top-down-syndrome-resources-you-should-know-about/