Down syndrome

Question 1

You are working as a GP in a rural town. On a routine 6 week baby check, you notice that the term baby has poor tone, single palmar creases, down slanting eyes with epicanthic folds and low set ears.

Answer 1

Impression
The salient features of this stem are the examination findings suggestive of Down syndrome or Trisomy 21.

DDx
- Syndromic: Fragile X, Turners
- congenital: Fetal alcohol syndrome
- isolated congenital hypotonia (floppy baby)
- congenital hypothyroid

Down syndrome is associated with a number of systemic and multi system issues including; cardiac, GIT, ophthalmic, respiratory, neurological, and endocrine anomalies.

Goals
- conduct comprehensive assessment to confirm diagnosis and to screen for evidence of multi system complications
- arrange appropriate follow-up and surveillance/screening and subsequent early intervention for any systemic manifestations to improve quality of life.

Question 2

Down syndrome - History

Answer 2

History
- confirm babies age
- Sx: respiratory sx (dyspnoea, SOB, WOB, recurrent infection, GIT upset/changes, heart murmurs, visual/auditory problems
- Maternal factors: maternal age, obstetric history - scans and any abnormalities, any screening/diagnostic tests for DS during pregnancy? results of these.
- Screening: PAPP-A (reduced), nuchal translucency (elevated), ß-HCG (elevated),
- GTPAL, other defects in other living children.
- Paediatric Hx: vaccinations, developmental milestones

Question 3

Down syndrome - Examination

Answer 3

Examination
- General appearance: down-slanting eyes, epicanthal folds, single palmar crease, small down-set ears, broad nasal bridge, indistinct philtrum, brushfield spots (white stars), cataracts, anal patency, cryptorchidism, etc
- Baby check and systems review
o cardiac: murmurs
o ophthalmic: dull cornea, absent red reflex
o abdo: swelling, tenderness
o MSK: general hypotonia, DDH

Question 4

Down syndrome - Investigations

Answer 4

Investigations
Diagnostic
- chromosomal analysis to confirm trisomy 21 (karyotuping)

Ancillary - screening for complications
- Cardiac: echo, ECG, CXR
- GIT: AXR
- ophthalmic examination (may require referral)
- formal hearing test
- bloods: FBC, UEC, LFT, TFT

Question 5

Down syndrome - management

Answer 5

Management
Supportive
- congratulate parents on having a baby
- document concerns/worries, reassurance about quality of life etc
- any relevant counselling, directions for support groups
(Down syndrome Australia) etc, referral to clinical geneticist re family planning etc.
- provide fact sheets

Definitive
- MDT and ongoing surveillance + screening for morbidity associated with

Face: cleft palate, epicanthal folds, flat nasal bridge
Ophthal: congenital cataract, brushfield spots
GIT: intestinal atresia, imperforate anus, coeliac disease, hirschprung’s disease
Cardiac: ASD and ASVD
MSK: hypotonia, simmean crease, atlanto-axial instability
other
- OSA
- hypothyroid
- haematological malignancy