easy understandable one

1. Emre
YARDIMCI
Dönem 1
216015

2. Down Syndrome
Trisomy 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 21
is a chromosomal disorder caused by the presence of
all or part of an extra 21st chromosome. It is named
after John Langdon Down, the British doctor who
described the syndrome in 1866.

5. The disorder was
identified as a
chromosome 21
trisomy by
Jérôme
Lejeune in
1959.

6. The condition is characterized by a
combination of major and minor
differences in structure. Often Down
syndrome is associated with some
impairment of cognitive ability and
physical growth as well as facial
appearance.

7. Down syndrome
in a baby can be
identified with
amniocentesis
during
pregnancy or at
birth.

8. Individuals with Down syndrome tend
to have a lower than average cognitive
ability, often ranging from mild to
moderate developmental disabilities.

9. A small number have severe to
profound mental disability. The
incidence of Down syndrome is
estimated at 1 per 800 to 1,000
births, although these statistics are
heavily influenced by the age of the
mother.

10. Other factors may
also play a role

11. Physical characteristics
single transverse palmar crease
upslanting palpebral fissures
poor muscle tone
protruding tongue
a larger than normal space between the
big and second toes

13. Health complications
 Congenital heart defects
 Leukemia
 Gastrointestinal problems
 Abnormal immune system
 Eye disorders, hearing loss
 Obstructive sleep apnea
 Early Dementia

14. PHYSICAL
CHRACTERISTICS

15. Common physical features

16. oblique eye
fissures with
epicanthic skin
folds on the inner
corner of the eyes

17. muscle hypotonia (poor muscle tone)

18.  a single palmar fold

19. a flat nasal bridge

20. a protruding tongue (due to small oral
cavity, and an enlarged tongue near
the tonsils)

21. white spots on the iris known as
Brushfield spots

22. a larger than
normal space
between the big
and second toes

23. Genetics
 Trisomy 21
 Mosaicism
 Robertsonian translocation
 Duplication of a portion of
chromosome 21

24. Down syndrome is a chromosomal
abnormality characterized by the
presence of an extra copy of genetic
material on the 21st
chromosome, either in whole (trisomy
21) or part (such as due to
translocations

26. The effects of the extra copy vary
greatly among people, depending on
the extent of the extra copy, genetic
history, and pure chance.
Down syndrome occurs in all human
populations, and analogous effects
have been found in other species such
as chimpanzees and mice

28. The extra chromosomal material can
come about in several distinct ways. A
typical human karyotype is designated
as 46,XX or 46,XY, indicating 46
chromosomes with an XX arrangement
typical of females and 46 chromosomes
with an XY arrangement typical of
males

29. Trisomy 21
(47,XX,+21) is caused by a meiotic
nondisjunction event.

31. With nondisjunction, a gamete
(i.e., a sperm or egg cell) is
produced with an extra copy of
chromosome 21; the gamete thus
has 24 chromosomes.

32. When combined with a normal
gamete from the other parent, the
embryo now has 47
chromosomes, with three copies of
chromosome 21

33. Chromosomal nondisjunction

34. Trisomy 21 is the cause of
approximately 95% of observed
Down syndromes, with 88%
coming from nondisjunction in the
maternal gamete and 8% coming
from nondisjunction in the
paternal gamete

35. Mosaicism
Trisomy 21 is usually caused by
nondisjunction in the gametes prior to
conception, and all cells in the body are
affected. However, when some of the
cells in the body are normal and other
cells have trisomy 21, it is called mosaic
Down syndrome (46,XX/47,XX,+21).

36.  This can occur in one of two ways: a
nondisjunction event during an early cell
division in a normal embryo leads to a
fraction of the cells with trisomy 21; or a
Down syndrome embryo undergoes
nondisjunction and some of the cells in
the embryo revert to the normal
chromosomal arrangement.

37. • There is considerable
variability in the
fraction of trisomy
21, both as a whole
and among tissues

38. This is the cause of 1–
2% of the observed
Down syndromes.

39. Robertsonian translocation
 The extra chromosome 21 material that causes
Down syndrome may be due to a
Robertsonian translocation in the karyotype
of one of the parents. In this case, the long
arm of chromosome 21 is attached to another
chromosome, often chromosome 14
(45,XX, t(14;21q)) or itself (called an
isochromosome, 45,XX, t(21q;21q))

40. Duplication of a portion of
chromosome 21
Rarely, a region of chromosome 21 will
undergo a duplication event
This will lead to extra copies of some,
but not all, of the genes on
chromosome 21 (46,XX, dup(21q)).

41. The incidence
The incidence of Down syndrome is
estimated at one per 800 to one per
1000 births.
In 2006, the Centers for Disease
Control and Prevention estimated the
rate as one per 733 live births in the
United States (5429 new cases per year)

42. Risk factors for DS
 Older maternal age
 Older paternal age
 Already having a
child with DS
 Carriers of the
genetic translocation

43. About 90 percent of pregnant
women who are given a Down
syndrome diagnosis have chosen
to have an abortion.

44. At maternal age 20 to 24, the
probability is one in 1562; at age 35
to 39 the probability is one in
214, and above age 45 the
probability is one in 19.

45. Maternal age influences the chances of conceiving a
baby with Down syndrome

46. Prognosis for DS
Adults with good self-help skills
can be expected to live into
.
their 50s
Those with poor self-help skills
and live into their 40s.
Their lifespan continues to
increase

47. Down syndrome Seniors
Mary Perry, aged 73
Peter Davison, died aged 68

48. Treatments for DS
No medical cure
Specialist team
Care team
Early
intervention
Countinuing self-
help skills

49. Cafe down at Ankara
 Waiters who are
with down
syndrome work at
this cafe
 Although that’s not
new all over the
world,it is the only
and the first in
Turkey

50. They dont give up
so they are fulled-
hopefull
On the other
hand,having
motivational
support makes
the works better


51. March 21
 The first World Down Syndrome Day was held on 21
March 2006

52. Do me a favour! smile 

53. Best
Regards!