What is Down Syndrome?
Down syndrome is a naturally occurring genetic condition in which a child is born with an extra copy of chromosome 21. As a result, certain genes on chromosome 21 are over-expressed, impacting an individual in many ways. Down syndrome affects each person differently; no individual is likely to exhibit all the characteristics commonly associated with Down syndrome.
Common Physical Characteristics:
- Flat bridge of the nose
- Simian crease on the palms
- Extra space between the big toe and adjacent toe
- An extra fold of skin around the eyes
- Widely spaced and upward-slanting eyes
- Straight hair
- Structural differences in the mouth and ears
- Short stature
Common Developmental Concerns:
- Neurological and cognitive differences
- Mild to moderate intellectual delays
- Behavioural issues
- Speech deficits
- Memory impairment
- Higher prevalence of autism spectrum disorder
Common Health Concerns:
- Heart defects
- Vision and hearing impairment
- Thyroid problems
- Respiratory issues
- Sleep disorders
- Mental health issues
- Gastrointestinal issues
- Dental problems
- Childhood leukemia
- Early-onset Alzheimer’s and dementia
Did You Know?
Approximately 1 in 800 babies born in Canada has Down syndrome. Genetically, there are three types of Down syndrome:
Trisomy 21: The most common type of Down syndrome, in which the person has a complete extra copy of the 21st chromosome
Translocation: A rarer type of Down syndrome, in which an additional full or partial copy of chromosome 21 is attached to a different chromosome (2-3% of people with Down syndrome)
Mosaicism: The rarest type of Down syndrome, in which only some cells in the body have a full extra copy of the 21st chromosome, and the rest of the cells are typical (1% of people with Down syndrome)
Though people with Down syndrome may share some common characteristics, each is a unique individual. Thanks to medical research, a better understanding of the condition, and shifting societal norms, people with Down syndrome can expect to live long, happy lives. We must continue to work together to build a world that values and empowers people with Down syndrome, fostering economic, social, and individual inclusion throughout their lives.
DSRF Resources
Down Syndrome Academy Online Course: Down Syndrome 101: An Introduction to Down Syndrome
A Quick Guide to Down Syndrome for Parents
The T21 Difference: Learning Profiles of Students with Down Syndrome
Other Resources
Historical Timeline for People with Disabilities (Inclusion Canada)