Down Syndrome

What is it?

A genetic (inborn or inherited) disorder, leading to challenges with cognition (thinking) and learning as well as some unique physical, medical and developmental issues.


Trisomy 21 – 3 copies (instead of 2) on chromosome 21 ("tri" means "3" and "somy" refers to "chromosomes"). We all have 26 pairs ("body") chromosomes and "1" pair ("sex") chromosomes – either XX for femal and XY for males.


It's the commonest inherited cause of intellectual disabilities. Researchers have established that the likelihood that a reproductive cell will contain an extra copy of chromosome 21 increases dramatically as a woman ages.


Mothers Age Incidence of Down Syndrome
Under 30 Less than 1 in 1,000
30 1 in 900
35 1 in 400
36 1 in 300
37 1 in 230
38 1 in 180
39 1 in 135
40 1 in 105
42 1 in 60
44 1 in 35
46 1 in 20
48 1 in 16
49 1 in 12

Common Physical Traits

All have resemblance or physical features in common, which makes them easily recognizable: flattened facial profile, upward slant eyes, low muscle tone (this makes them appear open-mouthed as well) and a single deep crease across the centre of 1 or both palms.

Other traits (not visible)

Medical Issues, like Congenital Heart Disease. (>80%) abnormalities of the gastrointestinal system, hearing and / or visual impairment, some type/s of hormonal problems e.g. thyroid, intellectual disabilities (mild-moderate-severe).

How its diagnosed

  • Recognition of clinical features: Usual method used.
  • Genetic Testing - not routinely carried out, cannot predict long term outcome or potential of the child or even how severely all the features will be.


May not need all types of therapies during life span:

  • Speech Therapy
  • Occupational Therapy (OT)
  • Physical Therapy or Physiotherapy (PT)
  • Special Education – Some are able to attend a regular or mainstream school and some cases even finish tertiary education.
  • Specialised Medical Care /Treatments

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