reference: ghai textbook of pediatrics pediatric topic

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