Down Syndrome

Question 1

What is the result of Trisomy 21?

Answer 1

Down Syndrome

Question 2

What is the incidence of DS?

Answer 2

1: 600 - 800 births

Question 3

What is the most common abnormality of autosomal chromosomes?

Answer 3

Trisomy 21

Question 4

How does risk of T21 change with maternal age?

Answer 4

1:1500 at age 20 to 1:20 at 45y

Question 5

What are the cranial / brain features of T21?

Answer 5

• Mild microcephaly
• Flat occiput
• 3rd fontanelle
• Brachycephaly

Question 6

What are the eye features of T21?

Answer 6

• Upslanting palpebral fissures
• Inner epicanthal folds
• Speckled iris (Brushfield spots)
• Refractive errors (myopia)
• Acquired cataracts
• Nystagmus
• Strabismus

Question 7

Ear features of T21?

Answer 7

• Low, small set ears with over-folded upper helix
• Frequent AOM
• Hearing loss

Question 8

Facial features of T21?

Answer 8

• protruding tongue
• large cheeks
• low flat nasal bridge
• small nose

Question 9

Skeletal / MSK features of T21?

Answer 9

• Short stature
• Excess nuchal skin
• Joint hyper flexibility (80%) inc dysplastic hips, vertebral anomalies, atlantoaxial instability

Question 10

Cardiac defects a/w T21?

Answer 10

50% esp AVSD

Question 11

GIT defects a/w T21?

Answer 11

• Duodenal / oesophageal / anal atresia
• TOF
• Hirschsprung’s disease
• Chronic constipation

Question 12

GUT changes with T21?

Answer 12

• Cryptorchidism.

- Rarely fertile

Question 13

CNS features of T21?

Answer 13

• Hypotonia at birth
• Low IQ
• Developmental delay
• Hearing problems
• Onset of AD in early 40s

Question 14

Hand features of T21?

Answer 14

• Transverse, single palmar crease
• Clinodactyly
• Absent middle phalanx of 5th finger

Question 15

What are common medical conditions concurrent with T21?

Answer 15

• Polycythemia
• Hypothyroidism
• 1% lifetime risk of leukemia

Question 16

Prenatal management for children with T21?

Answer 16

• Counselling
• Plan for delivery
• Geneticist referral

Question 17

What should be conducted prior to discharge from hospital for baby with T21?

Answer 17

• PEx: for T21 features esp CV, GIT, opthal complications
• Chromosomal analysis to confirm
• Genetic counselling (risk of recurrence)
• Echo
• Audiology and ENT assessment
• TSH

Question 18

What should be considered in child with T21 who is constipated?

Answer 18

• Hypotonia
• Hypothyroidism
• GIT anomalies
• Hirschprung’s