Down syndrome. pdf diagnosis and screening by DR. Khansa

Down syndrome :
introduction
pathology
epidemiology
clinical features
systemic diseases
associated conditions
diagnosis and screening
management

1. Down’s syndrome by DR.KHANSA

2. CONTENT Introduction Epidemiology Pathology Clinical findings Systemic conditions Associated conditions Genetic counseling Diagnosis and screening Management

3. INTRODUCTION Down syndrome is the most common genetic disorder. It is autosomal trisomy, compatible with life. The basic defect is trisomy , i.e. there are 47 chromosome instead of 46.

4. Epidemiology 92% of children with Down syndrome have 47 chromosomes , with three 21 chromosomes. The additional 21 chromosome is derive from mother in 80% of cases Trisomy 21 occur in 1 in 700 live births Recurrence risk for parents who have had a child with down syndrome is 5 to 7 % Chromosomal non disjunction is responsible for 80 to 92% of cases of trisomy 21

5. Pathology Down syndrome occurs due to one of the following defects Translocation : when chromosome breaks off and attach to another chromosome.it is the most common defect. 5% of children with down syndrome have this defect Mosaicism : when mixture of two type of cells are present.it is rare . 3% of children with down syndrome have this defect.

6. Clinical features Generalized hypotonia Flat occiput Delayed closure of frontanelle Nasal bridge is flat Flat facies

7. Clinical features Low set ears Large and protruding tongue Brush field spots on iris Lens opacities

8. Clinical features Delayed tooth eruption with abnormal positioning Fine and sparse hair Cutis marmorata : velvety, loose adhering ,mottled skin

9. Clinical features Short and broad digits, feet and hands Lax joints IQ 20 to 75 Affectionate and good humor Delayed development of secondary sexual characters males are infertile

10. Systemic conditions CVS lesions : Atrioventricular canal TOF VSD Blood defects : Under 2 years of age: megakaryocytic acute myelogenous leukemia Older children: acute lymphoblastic leukemia Bowel defects duodenal atresia Tracheoesophageal atresia Annular pancreas Hirschprung’s disease

11. Associated conditions Hypothyroidism Physiological jaundice Polycythemia Umbilical hernia Transient leukemoid reaction

12. Clinical features Brush field spots On iris Simian crease On hands Protruding tongue Due to small oral cavity

13. Clinical features Wide space between 1 st and 2 nd toe clinodactyly Of little finger Simian crease On hands

14. Genetic counseling Incidence of down syndrome increase with increase maternal age.

15. Diagnosis and screening Clinical picture Karyotyping Triple screening test Quad screen Ultrasound scan in 1 st trimester : increase nuchal translucency Examinaton of fetal cell chromosome by amniocentesis or chorionic villus sampling

16. Triple and Quad screen

17. Management NO SPECIFIC TREATMENT Symptomatic treatment Antibiotics for infections Heart surgery for cardiac defects Support for parents for family planning advice is important

18. Thank you