Down syndrome is the most common chromosomal disorder, occurring in 1 in 800-1000 births. It is caused by trisomy 21 in 94% of cases. Clinical features include intellectual disability, flat facial features, upward slanted eyes, small nose, short hands and feet, and other physical signs. Associated medical issues are also common, such as congenital heart defects in 40% of individuals. Management involves early intervention services and treating associated medical problems. While life expectancy has increased, individuals with Down syndrome still face higher risks of certain health issues.

1. Down syndrome
By Godfrey dijoe

2. Most common chromosomal disorder (frequency of 1:800 –
1:1000 newborns).
It is the most common causes of mental retardation.
Occurs more often when the mother conceive at older age.

3. Cytogenetics:
Trisomy 21 is found in 94% cases
Approximately 1 % of cases are mosaic and the rest (5%) are due
to translocations, most commonly involving chromosomes 21
and 14.

4. Clinical features and diagnosis
 mental and physical retardation,
 flat facial profile
 an upward slant of eyes and epicanthic folds
 Oblique palpebral fissure
 The nose is small with flat nasal bridge.
 short palate with small teeth and furrowed protruding tongue.
 significant hypotonia.
 skull appears small and brachycephalic with flat occiput

5.  Ears are small and dysplastic
 facial grimace on crying.
 Hands are short and broad
 Clinodactyly
 simian crease are usual.
 There is a wide gap between the first and the second toe (sandle gap).

7. Associated abnormalities
1. Congenital heart disease:-40%
-Endocardial cushion defects -40-60% cases.
2. Gastrointestinal malabsorption:
- Atresias in 12% of cases (esp duodenal atresia)
- Increase risk of annular pancreas and Hirschprung disease.
3. Eye problems - Increase risk of cataract, nystagmus, squint, and abnormalities of
visual acuity
4. Hearing defects - Prone to serious otitis media.

8. 5. Thyroid dysfunction - 13-54% have hypothyroidism.
- Thyroid function test recommended during neonatal period
6. Atlanto-occipital subluxation
- Displacement of atlanto-occipital joint can cause cord
compression.
- 10-30% cases

9. 7. Physical growth.
- Linear growth is retarded and tend to become obese with age. - Muscle
tone improves with age whereas the developmental progress slows with
age.
- Regular follow up for height and weight is necessary.
8. Malignancies
- Prone to develop lymphoproliferative disorders, including acute
lymphoblastic leukemia (ALL) , acute myeloid leukemia (AML) ,
myelodisplasia and transient lymphoproliferative syndrome

10. Management and Prognosis
 Principle : early stimulation, physiotherapy and speech therapy.
 Associated problems need to be treated as required.
 Social performance is usually achieved beyond that expected for mental
age.
 They behave as happy children, friendly, good sense of rhythm and
enjoy music

11.  Major cause of early mortality is CHD (almost 50% die in infancy)
 Other common diseases :
-Chronic rhinitis
-Conjunctivitis
-Periodontal disease
 Lower respiratory tract infections and hematological malignancies are
another cause of increased mortality.

12. Counseling
 The parents should be :
 1. Informed about the disorder as early as possible after diagnosis is
confirmed.
 2. Talk in simple and positive language giving hope, and allow sufficient
time to the parents to ask questions.
 3. Discuss known problems and associated disorders.
 4. Not talk about institutionalisation and adoption, unless asked. Both
these options should be discouraged.
 5. Inform about recurrence risks and possibilities of prenatal diagnosis

13. Risk of Recurrence
Women age 35 years or less who have a child with trisomy
have a 1% risk of having another.
Risk is little increased if the mother is at risk and 35 years or
older.
For translocations inherited from the mother, the risk is about
10% and 4-5% if inherited from father

14. evaluation Frequency of accessment
growth Twice a year in firstyear;annually
till 5 yearauditory
ocular
Thyroid profile
Cardiac evaluation At initial contact;follow up if chd
hematology Screen for leukemia twice ayear
first year;monitor as per need
dental annually
Evaluation in patient with down syndrome

15. Thank you