1. DOWN SYNDROME

2. Down syndrome In every cell in the human body there is a nucleus, where genetic material is stored in genes. Genes carry the codes responsible for all of our inherited traits and are grouped along rod-like structures called chromosomes. Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. There are 3 variations of down syndrome: Trisomy 21 (nondisjunction) Mosaic Translocation

3. Trisomy 21 (nondisjunction) Down syndrome is usually caused by an error in cell division called "nondisjunction." Nondisjunction results in an embryo with three copies of chromosome 21 instead of the usual two. Prior to or at conception, a pair of 21st chromosomes in either the sperm or the egg fails to separate. As the embryo develops, the extra chromosome is replicated in every cell of the body. This type of Down syndrome, which accounts for 95% of cases, is called trisomy 21. TYPICAL CELL DIVISION TRISOMY 21 (NONDISJUNCTION) CELL DIVISION

4. Mosaic Down syndrome In a very rare number of Down syndrome cases (about 1–2%), the original egg and sperm cells are completely normal. The problem occurs sometime shortly after fertilization; during the phase where cells are dividing rapidly. One cell divides abnormally, creating a line of cells with an extra chromosome 21. This form of genetic disorder is called a mosaic. The individual with this type of Down syndrome has two types of cells: those with 46 chromosomes (the normal number), and those with 47 chromosomes (as occurs in Down syndrome). Some researchers have suggested that individuals with this type of mosaic form of Down syndrome have less severe signs and symptoms of the disorder.

5. Mosaic Down syndrome

6. Translocation Down syndrome In translocation, which accounts for about 4% of cases of Down syndrome, the total number of chromosomes in the cells remains 46; however, an additional full or partial copy of chromosome 21 attaches to another chromosome, usually chromosome 14. The presence of the extra full or partial chromosome 21 causes the characteristics of Down syndrome.

7. Translocation Down syndrome Different variations of translocation:

8. Physical Features Some common physical features of Down syndrome include: A flattened face, especially the bridge of the nose Almond-shaped eyes that slant up A short neck Small ears A tongue that tends to stick out of the mouth Tiny white spots on the iris (colored part) of the eye Small hands and feet A single line across the palm of the hand (palmar crease) Small pinky fingers that sometimes curve toward the thumb Poor muscle tone or loose joints Shorter in height as children and adults

9. Physical Features

10. Mental Health Related Concerns Young and early school age children: Disruptive, impulsive, inattentive, hyperactive and oppositional behaviors, Chronic sleep difficulties, daytime sleepiness, fatigue Older school age children and adolescents: Depression, social withdrawal, diminished interests and coping skills Generalized anxiety, Obsessive compulsive behaviors Regression with decline in loss of cognitive and social skills Older adults present with increased vulnerability to: Generalized anxiety Depression, social withdrawal, loss of interest, and diminished self-care Regression with decline in cognitive and social skills Dementia

11. Other Health Problems Many people with Down syndrome have the common facial features and no other major birth defects. However, some people with Down syndrome might have one or more major birth defects or other medical problems. These include: Hearing loss (up to 75% of people with Down syndrome may be affected) Obstructive sleep apnea, which is a condition where the person’s breathing temporarily stops while asleep (between 50 -75%) Frequent Ear infections (between 50 -70%) Eye diseases (up to 60%), like cataracts and eye issues requiring glasses Heart defects present at birth (50%)

12. less common health problems Other less common health problems among people with Down syndrome include: Hirschsprung disease(intestine blockage due to poor muscle movement) Hip dislocation Thyroid disease Anemia (red blood cells can’t carry enough oxygen to the body) and iron deficiency (anemia where the red blood cells don’t have enough iron) Leukemia in infancy or early childhood

13. What is the Likelihood of Having a Child with Down Syndrome? Down syndrome occurs in people of all races and economic levels, though older women have an increased chance of having a child with Down syndrome. A 35 year old woman has about a one in 350 chance of conceiving a child with Down syndrome, and this chance increases gradually to 1 in 100 by age 40. At age 45 the incidence becomes approximately 1 in 30. The age of the mother does not seem to be linked to the risk of translocation.

14. Diagnosis There are two basic types of tests available to detect Down syndrome during pregnancy. Screening tests are one type and diagnostic tests are another type. A screening test can tell a woman and her healthcare provider whether her pregnancy has a lower or higher chance of having Down syndrome. So screening tests help decide whether a diagnostic test might be needed. Screening tests do not provide an absolute diagnosis, but they are safer for the mother and the baby. Diagnostic tests can typically detect whether or not a baby will have Down syndrome, but they can be more risky for the mother and baby. Neither screening nor diagnostic tests can predict the full impact of Down syndrome on a baby

15. Screening tests Screening tests often include a combination of a blood test, which measures the amount of various substances in the mother’s blood (MS-AFP, Triple Screen, Quad-screen), and an ultrasound, which creates a picture of the baby. During an ultrasound, one of the things the technician looks at is the fluid behind the baby’s neck. Extra fluid in this region could indicate a genetic problem. These screening tests can help determine the baby’s risk of Down syndrome. Rarely, screening tests can give an abnormal result even when there is nothing wrong with the baby. Sometimes, the test results are normal and yet they miss a problem that does exist.

16. Diagnostic Tests Diagnostic tests are usually performed after a positive screening test in order to confirm a Down syndrome diagnosis. Types of diagnostic tests include: Chorionic villus sampling (CVS)—examines material from the placenta Amniocentesis—examines the amniotic fluid (the fluid from the sac surrounding the baby) Percutaneous umbilical blood sampling (PUBS)—examines blood from the umbilical cord These tests look for changes in the chromosomes that would indicate a Down syndrome diagnosis.

17. Treatments for Down Syndrome There is no single, standard treatment for Down syndrome. Treatments are based on each individual's physical and intellectual needs as well as his or her personal strengths and limitations A child with Down syndrome likely will receive care from a team of health professionals, including, but not limited to, physicians, special educators, speech therapists, occupational therapists, physical therapists, and social workers. All professionals who interact with children with Down syndrome should provide stimulation and encouragement.