Down Syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of a third copy of chromosome 21. It is the most common chromosome abnormality in humans, occurring in about 1 in 699 births in the US. Down Syndrome can be broken into three main types - trisomy 21 which accounts for 95% of cases, translocation Down Syndrome which is 3-4% of cases, and mosaic Down Syndrome which is less than 1% of cases. Physical features include stunted growth, slanted eyes, low-set ears, flattened nose, smaller teeth and shortened hands. Individuals with Down Syndrome often have intellectual disabilities ranging from mild to moderate and may experience delays in speech, motor skills,

1. Down Syndrome
Sallyanna Cohen

2. AKA “trisomy 21” because it is a
genetic disorder caused by
having a 3rd copy of
chromosome 21 (most common
form)
The most common chromosome
abnormality in humans
1 out of 699 babies born in the
U.S. are born with Down
Syndrome
Background Information

3. Different Types
of
Down Syndrome
① Trisomy 21: account for 95% -extra chromosome 21 (three rather
than a pair)
② Translocation Down Syndrome: 3-4% of people with Down
Syndrome-extra #21 chromosome is present, but attached to a diff
chromosome in the egg or sperm
③ Mosaic Down Syndrome: account for <1%- born having some cells
with 3 copies of chromosome 21 and some with the usual pair;
usually have same features and health problems as the other
types, but may result in fewer characteristics- also may score a few
points higher in IQ

4. Physical Features
 Stunted growth
 Upward slanted eyes & eyelid crease
 Low-set and rounded ears
 Flattened nose
 Smaller teeth
 Shortened hands

5. Neurological Symptoms
o Most have intellectual disability in the
mild (IQ 50-70) to moderate (IQ 35-50)
range
o Common to have a speech delay
o Delay in gross & fine motor skills
o Greater risk for developing epilepsy
and Alzheimer’s Disease

6. Prenatal Testing
 The highest detection rate in
screening is from a combined test
using ultrasound (Nuchal
translucency/free beta hCG/PAPP-A
screen)
 Blood Tests

7. Post Natal
 Fried’s Diagnostic Index :
- Detects 8 characteristics
- if the baby has 0-2 characteristics it
is likely to not have the syndrome
- 3-5 characteristics its unclear
- 6-8 characteristics they are
confident he or she has Down
Syndrome

8. Adaptive Skills
• Children with Down Syndrome do
seem to acquire skills in a similar
sequence as regular children in
adaptive levels of motor, daily
living, communicative, and social
behavioral skills but at a slower pace
and reach their ceiling at about the
age of 12
• Most, depending on the intensity of
the syndrome, are able to live
independently and hold job

9. Interventions
 Screen for middle ear problems and
hearing loss- hearing aids or other
amplification devices can be useful for
language learning
 Early communication intervention
fosters linguistic skills
 Language assessments can help
profile strengths and weaknesses
 Individualized speech therapy
 Augmentative and alternative
communication (AAC) methods such
as pointing, body language, objects, or
graphics are often used to aid
communication