DOWNS SYNDROME (PPT)
- 2. What is Down Syndrome? • Down syndrome is a genetic disorder that causes a lifelong Intellectual Disability, developmental delays and other problems • Down syndrome varies in severity, so developmental problems range from moderate to serious • Down syndrome is the most common genetic cause of learning disabilities in children • Increased understanding of Down syndrome and early interventions make a big difference in the lives of both children and adults with Down syndrome
- 3. Causes • Human cells normally contain 23 pairs of chromosomes—one chromosome in each pair comes from the father, the other from the mother • Down syndrome results when one of three types of abnormal cell division involving chromosome 21 occurs • All three cell division abnormalities result in extra genetic material from chromosome 21, which is responsible for the characteristic features and developmental problems of Down syndrome • The three genetic variations that can cause Down syndrome include: – Trisomy 21 – Mosaic Down syndrome – Translocation Down syndrome
- 4. Types of Down Syndrome –Trisomy 21 (95%) • Three chromosomes 21 in every cell –Translocation (3-5%) • Extra part of chromosome 21 attaches to another chromosome in every cell –Mosaic 1-2 % • Mixture of cells, some with an extra chromosome 21 and others with just two
- 5. Trisomy 21 • More than 90 percent of the time, Down syndrome is caused by trisomy 21 • A child with trisomy 21 has three copies of chromosome 21 — instead of the usual two copies — in all of his or her cells • This form of Down syndrome is caused by abnormal cell division during the development of the sperm cell or the egg cell
- 6. Mosaic Down syndrome • In this rare form of Down syndrome, children have some cells with an extra copy of chromosome 21 • This mosaic of normal and abnormal cells is caused by abnormal cell division after fertilization
- 7. Translocation Down syndrome • Down syndrome can also occur when part of chromosome 21 becomes attached (translocated) onto another chromosome, before or at conception • Children with translocation Down syndrome have the usual two copies of chromosome 21, but they also have additional material from chromosome 21 attached to the translocated chromosome • This form of Down syndrome is uncommon
- 8. Nature vs. Nurture • There are no known behavioral or environmental factors that cause Down syndrome
- 9. Is it inherited? • Most of the time, Down syndrome isn't inherited. It's caused by a mistake in cell division during the development of the egg, sperm or embryo • Translocation Down syndrome is the only form of the disorder that can be passed from parent to child. However, only about 4% of children with Down syndrome have translocation. And only about half of these children inherited it from one of their parents
- 10. Risk Factors • Some parents have a greater risk of having a baby with Down syndrome • Risk factors include: – Advancing maternal age. A woman's chances of giving birth to a child with Down syndrome increase with age because older eggs have a greater risk of improper chromosome division. By age 35, a woman's risk of conceiving a child with Down syndrome is 1 in 400. By age 45, the risk is 1 in 35. However, most children with Down syndrome are actually born to women under age 35 because younger women have far more babies – Having had one child with Down syndrome. Typically, a woman who has one child with Down syndrome has about a 1% chance of having another child with Down syndrome – Being carriers of the genetic translocation for Down syndrome. Both men and women can pass the genetic translocation for Down syndrome on to their children
- 11. Common Symptoms • A distinct facial appearance: – Flattened facial features – Small head – Short neck – Protruding tongue – Upward slanting eyes, unusual for the child's ethnic group – Unusually shaped ears • Poor muscle tone • Broad, short hands with a single crease in the palm • Relatively short fingers • Excessive flexibility
- 12. Common Symptoms Continued… • Infants with Down syndrome may be of average size, but typically they grow slowly and remain shorter than other children of similar age • In general, developmental milestones, such as sitting and crawling, occur at about twice the age of children without impairment • Children with Down syndrome also have some degree of Intellectual Disability, most often in the mild to moderate range
- 14. Complications • Children with Down syndrome can have a variety of complications, some of which become more prominent as they get older, including: – Heart defects. Approximately half the children with Down syndrome are born with some type of heart defect. These heart problems can be life-threatening and may require surgery in early infancy. – Leukemia. Young children with Down syndrome are more likely to develop leukemia than are other children. – Infectious diseases. Because of abnormalities in their immune systems, those with Down syndrome are much more susceptible to infectious diseases, such as pneumonia
- 15. Complications Continued… • Dementia. Later in life, people with Down syndrome have a greatly increased risk of dementia. Signs and symptoms of dementia often appear before age 40 in people with Down syndrome. Those who have dementia also have a higher rate of seizures • Sleep apnea. Because of soft tissue and skeletal alterations that lead to the obstruction of their airways, children with Down syndrome are at greater risk of obstructive sleep apnea • Obesity. People with Down syndrome have a greater tendency to be obese than does the general population • Other problems. Down syndrome may also be associated with other health conditions, including gastrointestinal blockage, thyroid problems, early menopause, seizures, hearing loss, premature aging, skeletal problems and poor vision
- 16. Life Expectancy • Life spans have increased dramatically for people with Down syndrome • In 1929, a baby born with Down syndrome often didn't live to age 10 • Today, someone with Down syndrome can expect to live to 50 and beyond, depending on the severity of his or her health problems
- 17. Early Intervention • Early intervention for infants and children with Down syndrome can make a difference in realizing their potential abilities and in their quality of life • Early intervention programs vary from state to state, but they usually involve therapists and special educators whose goal is to help the baby develop motor skills, language, social skills and self-help skills
- 18. Is There A Cure For Down Syndrome? • No, there is no cure. • It cannot be prevented • Scientists do not know why problems involving chromosome 21 occur. • Down syndrome is not caused by anything either of the parents did or did not do.
- 19. Effects On Speech Expressive language of children with Down syndrome is commonly more delayed than receptive language (SUJEET Desai, 1997).
- 20. THANK YOU