everything regarding DOWN'S SYNDROME is given with updates.

2. 1 in 650 to 700.
This condition derives its name from Dr.
Langdon Down ,who first described it in the
clinical lecture reports of the London
hospital in 1866.

3. Abnormality Frequency (%)
Trisomy 21.
(nondisjunction of chr.-21
in maternal meiosis – 1).
95
Robertsonian translocation
–D/G-(21q/21q , 22q/21q )
4
Mosaicism
(Often less severely
affected than those with
full syndrome.)
1

4. 0
10
20
30
40
50
60
70
80
90
100
TRISOMY 21 ROBERTSONIAN
TRANSLOCATION
MOSAICISM
TRISOMY 21 ROBERTSONIAN TRANSLOCATION MOSAICISM

5. •Cause •Recurrence risks
Trisomy 21 1/200 to 1/100
Translocation Male:1-3%
Female:10-15%
Translocation between 21q
& 21q
100%

6.  Newborn period: Hypotonia , sleepy excess nuchal skin .
 Craniofacial: Brachycephaly ; epicanthic folds & brush-field spots on eye
; upward sloping palpebral fissures ; protruding tongue ; small ears ; flat
nasal bridge .
 Limbs: Single palmar crease ( “simian crease” ) , small middle phalanx of
5th finger , wide gap between 1st & 2nd toes .
 Cardiac: Atrial & ventricular septal defect ; common atrioventricular
canal ; patent ductus arteriosus .
 Others:
 Anal atresia , duodenal atresia , Hirsch-prung disease.
 Short stature , strabismus .
 Average I.Q. of young adults is around 40 to 45(RANGE→20-50) .
 Social skills well-developed , most of the children are happy & very affectionate .
 May be associated with ALL & AML(M7) .
 Antibody against thyroid may develop- Autoimmune Thyroiditis.

7. They are susceptible to infection & often have congenital
heart disease ( in about 50% of all cases ). So , they usually
die young . Generally they have a lifetime of about 40 – 50
years , except in severe cases .

8. i) High resolution USG.
ii) Chorionic villus analysis .
iii) Cultured amniotic cells .
iv) FISH technique .
v) Prenatal screening programmes have been introduced based
on the so called “triple” or “quadruple” tests of maternal
serum at 16 weeks’ gestation .

14. Epicanthic fold
Flat nasal bridge
Protruding tongue
Karyotype:
Trisomy 21
Robertsonian translocation
Mosaicism
Simian crease
Brushfield spots
Epicanthic fold
Short ear
Protruding
tongueLarge gap
between 1st &
2nd toes

18. Questions?
Questions?
Questions?
Questions??