1. Emre YARDIMCI Dnem 1216015

2. Down SyndromeTrisomy 21 Not less, more.. 3. A short history and some basic info Phsical charecteristics Health complications Genetics The insedence Risk factors for DS Prognosis for DS Treatments for DS Cafe down at Ankara 4. John Langdon Down Down syndrome, Down's syndrome, or trisomy 21is a chromosomal disorder caused by the presence ofall or part of an extra 21st chromosome. It is namedafter John Langdon Down, the British doctor whodescribed the syndrome in 1866. 5. The disorder wasidentified as achromosome 21trisomy byJrmeLejeune in1959. 6. The condition is characterized by acombination of major and minordifferences in structure. Often Downsyndrome is associated with someimpairment of cognitive ability andphysical growth as well as facialappearance. 7. Down syndromein a baby can beidentified withamniocentesisduringpregnancy or atbirth. 8. Individuals with Down syndrome tendto have a lower than average cognitiveability, often ranging from mild tomoderate developmental disabilities. 9. A small number have severe toprofound mental disability. Theincidence of Down syndrome isestimated at 1 per 800 to 1,000births, although these statistics areheavily influenced by the age of themother. 10. Other factors mayalso play a role 11. Physical characteristics single transverse palmar crease upslanting palpebral fissures poor muscle tone protruding tongue a larger than normal space between thebig and second toes 12. Health complications Congenital heart defects Leukemia Gastrointestinal problems Abnormal immune system Eye disorders, hearing loss Obstructive sleep apnea Early Dementia 13. PHYSICAL CHRACTERISTICS 14. Common physical features 15. oblique eyefissures withepicanthic skinfolds on the innercorner of the eyes 16. muscle hypotonia (poor muscle tone) 17. a single palmar fold 18. a flat nasal bridge 19. a protruding tongue (due to small oralcavity, and an enlarged tongue nearthe tonsils) 20. white spots on the iris known asBrushfield spots 21. a larger thannormal spacebetween the bigand second toes 22. Genetics Trisomy21 Mosaicism Robertsonian translocation Duplication of a portion of chromosome 21 23. Down syndrome is a chromosomalabnormality characterized by thepresence of an extra copy of geneticmaterial on the 21stchromosome, either in whole (trisomy21) or part (such as due totranslocations 24. The effects of the extra copy varygreatly among people, depending onthe extent of the extra copy, genetichistory, and pure chance. Down syndrome occurs in all humanpopulations, and analogous effectshave been found in other species suchas chimpanzees and mice 25. The extra chromosomal material cancome about in several distinct ways. Atypical human karyotype is designatedas 46,XX or 46,XY, indicating 46chromosomes with an XX arrangementtypical of females and 46 chromosomeswith an XY arrangement typical ofmales 26. Trisomy 21(47,XX,+21) is caused by a meioticnondisjunction event. 27. With nondisjunction, a gamete(i.e., a sperm or egg cell) isproduced with an extra copy ofchromosome 21; the gamete thushas 24 chromosomes. 28. When combined with a normalgamete from the other parent, theembryo now has 47chromosomes, with three copies ofchromosome 21 29. Chromosomal nondisjunction 30. Trisomy 21 is the cause ofapproximately 95% of observedDown syndromes, with 88%coming from nondisjunction in thematernal gamete and 8% comingfrom nondisjunction in thepaternal gamete 31. Mosaicism Trisomy 21 is usually caused bynondisjunction in the gametes prior toconception, and all cells in the body areaffected. However, when some of thecells in the body are normal and othercells have trisomy 21, it is called mosaicDown syndrome (46,XX/47,XX,+21). 32. This can occur in one of two ways: anondisjunction event during an early celldivision in a normal embryo leads to afraction of the cells with trisomy 21; or aDown syndrome embryo undergoesnondisjunction and some of the cells inthe embryo revert to the normalchromosomal arrangement. 33. There is considerablevariability in thefraction of trisomy21, both as a wholeand among tissues 34. This is the cause of 12% of the observedDown syndromes. 35. Robertsonian translocation The extra chromosome 21 material that causesDown syndrome may be due to aRobertsonian translocation in the karyotypeof one of the parents. In this case, the longarm of chromosome 21 is attached to anotherchromosome, often chromosome 14(45,XX, t(14;21q)) or itself (called anisochromosome, 45,XX, t(21q;21q)) 36. Duplication of a portion of chromosome 21Rarely, a region of chromosome 21 willundergo a duplication event This will lead to extra copies of some,but not all, of the genes onchromosome 21 (46,XX, dup(21q)). 37. The incidence The incidence of Down syndrome isestimated at one per 800 to one per1000 births. In 2006, the Centers for DiseaseControl and Prevention estimated therate as one per 733 live births in theUnited States (5429 new cases per year) 38. Risk factors for DS Older maternal age Older paternal age Already having a child with DS Carriers of thegenetic translocation 39. About 90 percent of pregnantwomen who are given a Downsyndrome diagnosis have chosento have an abortion. 40. At maternal age 20 to 24, theprobability is one in 1562; at age 35to 39 the probability is one in214, and above age 45 theprobability is one in 19. 41. Maternal age influences the chances of conceiving a baby with Down syndrome 42. Prognosis for DSAdults with good self-help skillscan be expected to live into .their 50s Those with poor self-help skillsand live into their 40s. Their lifespan continues toincrease 43. Down syndrome Seniors Mary Perry, aged 73 Peter Davison, died aged 68 44. Treatments for DSNo medical cure Specialist team Care team Earlyintervention Countinuing self-help skills 45. Cafe down at Ankara Waiters who are with down syndrome work at this cafe Although thats not new all over the world,it is the only and the first in Turkey 46. They dont give upso they are fulled-hopefull On the otherhand,havingmotivationalsupport makesthe works better 47. March 21 The first World Down Syndrome Day was held on 21March 2006 48. Do me a favour! smile 49. Best Regards!