Down Syndrome

Down syndrome (Down’s syndrome) is a genetic disorder causes by the presence of all or part of an extra copy of chromosome, i.e. the 21st chromosome called trisomy 21. 

Specialist Behaviour Support Services and Speech Pathology

small child with down syndrome playing with building blocks

Definition of Down Syndrome

Down syndrome (Down’s syndrome) is a genetic disorder causes by the presence of all or part of an extra copy of chromosome, i.e. the 21st chromosome called trisomy 21. 


Causes of Down Syndrome

In the process of reproduction, both parents pass on genes to their children. Genes are carried on chromosomes, so each cell receives 23 pairs of chromosomes from both parents to make 46 chromosomes. But due to some defect during division, one chromosome does not separate properly, leading to an increase in the number of chromosomes, i.e. one chromosome is extra, which is chromosome 21. This leads to defects in mental and physical health.


Types of Down Syndrome

There are three types of Down syndrome:

  • Trisomy 21 - this type of Down syndrome occurs when each cell in the body has 3 separate copies of chromosome 21 instead of the usual 2 copies.
  • Translocation - this type of Down syndrome occurs when a part of chromosome 21 or a whole extra chromosome 21 is present, but it is attached or translocated to a different chromosome rather than being a separate chromosome 21.
  • Mosaicism - this type of Down syndrome occurs when a child has an extra copy of a chromosome in some and not all cells means a mixture or combination of Trisomy 21 and Translocation.  


Symptoms of Down Syndrome

Physical symptoms:

  • Flat facial features.
  • Head and ears are small.
  • Short neck.
  • Protruding tongue.
  • Eyes slanting upward.
  • Aberrant shaped ears.
  • Substandard muscle tone.


  Developmental difficulties

  • Oral motor difficulties.
  • Fine motor and gross motor difficulties.
  • Learning difficulties.
  • Speech and language difficulties.
  • Impulsive behaviour.
  • Behavioural issues (e.g. stubbornness, non-compliance).
  • Poor judgment.
  • Short attention span.
  • Numeracy difficulties.
  • Verbal short term memory difficulties.

For more support with developmental difficulties see:


Possible medical complications: 

  • Heart anomalies present at the time of birth.
  • Hearing defects.
  • Poor eyesight and cataract (clouded eyes).
  • Interrupted breathing during sleeping, i.e. Sleep apnea.
  • Dementia.
  • Joint dislocations, specifically hip.
  • Obesity.
  • Defective tooth growth.
  • Underactive thyroid i.e. hypothyroidism.
  • Chronic constipation.
  • Dementia.
  • Alzheimer’s disease.



American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.).


Behaviour Help

If you are supporting an individual with this diagnosis, please refer to our services and resources. They aim to help children, adolescents and adults achieve better communication, social, emotional, behavioural and learning outcomes. So whether you are wanting guidance on parenting, teaching, supporting or providing therapy, Behaviour Help is at hand.

Note: This is not an exhaustive list of all the possible causes, symptoms and types but some general information that can be further explored. Based on what you have read if you have any concerns about an individual, please raise them with the individual/s. The caregiver can then raise these concerns with their local doctor who can provide a referral to the relevant professional (e.g. paediatrician, psychologist, psychiatrist, allied health professional and learning specialists) for diagnosis and treatment if appropriate.

Which resources are right for you?


Based on the Taking CHARGE of Rainbow of Emotions Workbook this app helps children of all ages develop emotional regulation skills. The app guides the child to firstly, identify and express their emotion in appropriate ways. Then the child is guided to use emotional management tool/s from the CHARGE tool kit to manage their emotions in a healthy way.

The acronym CHARGE stands for the different categories of emotional management tools – Chat tools, Helpful thinking tools, Amusement tools, Relaxation tools, Good routine tools and Exercise tools.

Behaviour Help App - Using the evidence-based approach of Positive Behaviour Support (PBS), the Behaviour Help web-based app allows people supporting individuals with emotional and behavioural difficulties to complete a Functional Behaviour Analysis and put together a comprehensive Behaviour Support Plan (BSP). The BSP can then be used by everyone interacting with the individual to manage and prevent challenging behaviours and ultimately improve their lives, and the lives of those who support them.


If you want to learn more about emotional and behavioural difficulties then we have a great range of books you can read on your Kindle or order from Amazon.


Personalised and practical one to one help tailored specifically to your family.

Online Courses

Access these online courses anytime online to learn about a range of diagnoses, practical skills and strategies to help develop the individual’s emotional regulation skills. Also learn to utilise the positive behaviour support framework to address anxiety, aggression, ADHD, ASD and ODD.

SEL Educational Videos

Minimise or eliminate the occurrence of challenging behaviours by teaching children of all ages appropriate ways of communicating, interacting, managing their emotions and behaviours.

The SEL curriculum uses video modelling to provide direct, explicit and systematic teaching of the various skills by discussing the importance of the skill, modelling the skill so the child learns what the skill looks like? sounds like? feels like? and learn the skill in staged situations that simulate real life scenarios.


Personalised and practical behaviour therapy tailored specifically to your family.


Webinars discuss a range of practical strategies to guide your child learn positive ways of behaving and managing their emotions.


Attend our practical and interactive workshops to learn about a range of diagnoses, practical skills and strategies to help develop the individual’s emotions, behaviours, social and communication skills in your learning environment.

Ask Dolly

Since you’re here, you probably have questions and concerns. I am Dolly Bhargava, am here to help. I am a NDIS registered behaviour support practitioner and speech pathologist.

I have worked in a number of settings for over 21 years so, how can I help?

Please tell me what is worrying you right now and I will do my best to recommend resources and/or services that will be most useful to you in your situation.

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