What is Down Syndrome? Understanding Trisomy 21 and Its Impact

Down syndrome is not your fault, nor is it the doctor’s. This guide exists to tell you why, and to teach you exactly what it is.

23 pairs of chromosomes make up a regular human being. This means you and everybody else you see have 46 chromosomes in total. These pairs come from the father and the mother of the child, who supply 23 each. They are responsible for the uniqueness of the human–basically, what determines your hair colour, eye colour, height and so on.

Chromosome 21 is the gene that’s responsible for cognitive development and immune system development. It is also responsible for other unique human traits, which science is yet to put a finger on. During the process of conception, a random genetic event can happen that splits one of the pairs of chromosome 21 from mum or dad. What happens next is that the foetus gets a 47th chromosome, which manifests as Down syndrome.

This genetic split is called “Trisomy 21” by doctors. This 47th chromosome cannot be deleted, overwritten or erased. Once created, it’s part of a human for life.

The key takeaway from this guide’s introduction is that none of it is your fault as a parent. Just as the Big Bang happened without anybody’s direct influence, the chromosome 21 split happened at the point of fertilisation without your influence.

Now you have some context. Let’s learn more about this condition.

How Does Down Syndrome Occur? (Trisomy 21 Genetics)

Doctors call the splitting of chromosome 21 Trisomy 21. This terminology comes from “tri”, meaning “three”, and “somy”, meaning “body”. It’s a pretty simple way to describe the fact that one chromosome has split, meaning that it appears as a triplet instead of a pair.

Here’s a quick fact for you: Each of the 46 chromosomes can be deleted totally or partially, or be split into two. In every instance of this happening, the child comes out of the mother with something lifelong. “Trisomy” is used to define the issue in the case of splitting. This means that “trisomy” can be used for all chromosomes, not just 21. There is Trisomy 18, Trisomy 13 and so on.

There’s no medically or scientifically justifiable reason for why or how the split happens, or what leads to it. Research on Down syndrome still goes on all over the world. But what we do know for a fact is that chromosome 21 is what shapes the baby’s brain and bodily functions, and that anything that goes wrong with it leads to a poorly developed baby.

Think of this split as sending an email twice, with one email carrying an extra line that confuses the receiver. In genetics, this split is called nondisjunction.

Let’s go back to our analogy. If you send an email twice, with one of them having an extra line or word, the easiest explanation is that you were tired or you lost your focus for a bit. This tiredness or loss of focus is typically a result of long hours of work or something of that nature.

Childbirth is kind of similar. Women can conceive up to menopause, but the longer they take to do it, the more their body “loses focus”. This “loss of focus” is what usually leads to nondisjunction, which splits chromosomes (in this case, chromosome 21, which manifests as Down syndrome).

It is easy to blame yourself if this looks like your story. But this split could’ve happened at your body’s prime, just like you could’ve sent that email twice without double-checking because you were over- or hyperactive and needed to clear as many tasks from your to-do list in a day. What this says is that even a 20-year-old could birth a child with Down syndrome.

Now, you have the facts of how it happens. Let us learn more about this syndrome and how you can live with it.

Trisomy 21 Diagnosis and Screening: Identifying Down Syndrome

The marvellous strides in medicine have made it such that a baby who will be born with Down syndrome can be spotted before they’re born. Imagine how life was for children born with this condition and their parents before medicine evolved to this point.

During antenatal checks and screenings at the hospital, doctors can run something called the Combined First Trimester Test. This is an ultrasound plus a blood test done when mum is 11–14 weeks in. This test can estimate the chance of Down syndrome.

As groundbreaking as that sounds, it’s already old school. Today, doctors run an even more accurate non-invasive prenatal test (NIPT) that will take a direct look at baby’s DNA from the mother’s blood. If this test spots something funny, doctors will immediately run diagnostic tests. One of those tests is to analyse baby’s chromosomes from a sample of the womb fluids, called amniocentesis. The answers from this test and others like it give a definite answer.

Even this is not enough to factually say that baby has Down syndrome. Mum and Dad will have to wait for the day of their due date. After birth, the doctor will have to do a chromosome count with a simple blood test. Once they spot chromosome 47 and trace it to chromosome 21 having split, then mum and dad will get their confirmation.

This is the norm in Australia, in fact. This has saved a lot of families and even pointed out other issues that would have been missed if the doctor had just declared that baby is a victim of Trisomy 21.

This is why those antenatal checks are important. Parents should never miss one if they can afford not to. Finding this out on time, even before baby is born, can help parents prepare for a special life ahead that may or may not involve the help of support services like Support Network.

Thankfully, Australian medical practitioners are empathetic enough to provide all the necessary care to a baby with Down syndrome from day one. Early detection just helps future planning.

What Does Down Syndrome Look Like? Facial and Bodily Features

Down syndrome leaves a very distinct mark on a person’s appearance. Don’t forget that chromosomes are responsible for how a human being looks. And so, if one chromosome has an issue, it will show outwardly.

In the case of Trisomy 21, the main physical features that cut across everybody who has it are:

1. Facial features

People living with Down syndrome have a flat face. Their noses don’t stand out as noses do on a human face, and their eyes look like slits. The same goes for their mouths, which are typically not enough to house their tongues, forcing them to have to leave their mouths hanging open.

2. Muscle tone & growth

People living with Down syndrome are smaller. They don’t grow at the same pace as regular humans, which is why you can see an elder with Down syndrome standing at the same height as a 10-year-old. Their muscles are also not the strongest, and this makes them a little clumsy. This low muscle tone, or “hypotonia”, also causes their tongues to grow much larger than their mouths, which also forces them to keep their mouths open.

3. Hands and feet

You know those lines that go from one side of the palm to the other? They’re called creases. People living with Down syndrome have one singular crease on their palms. It doesn’t affect how they use their hands, though. It’s just a distinct feature in people with Down’s. Their toes also have a “sandal gap”. This means there’s a very noticeable gap between their big toe and their second toe. It doesn’t hurt or cause trouble for them in any way, either. You may just have to replace a few slippers here and there, a little more often than you would want to.

4. Learning ability

Chromosome 21 primarily affects brain function and the immune system. When the chromosome splits, it affects everything. The brain will process information at a much slower rate, which means learning will become twice as tedious. Then, when you add the intellectual disability that nearly all people living with the condition have (dyslexia, dysgraphia, and the like), learning becomes four times as tedious. If you understand this from the start, you will be able to create learning plans that they can work with.

5. Health

As for their health, they’re more likely to have issues. From day 1, doctors are already monitoring their heart health, hearing, growth, and so on, so parents of children born with this genetic condition can rest assured. It is this monitoring that has brought us to the realisation that about 50% of babies with Down syndrome are born with a heart defect. Also, around 10% may have issues with their digestive systems. The most common ones are hearing and vision problems, where many children have to be fitted with special glasses and/or hearing tubes. The list is long.  If you detect it early enough, though, you can stay ahead.

People living with Down syndrome have gone on to become superstars in different fields. Madeline Stuart, the world’s first professional model with Down syndrome, is a proud Australian. Chris Dyke, an Australian with Down syndrome, achieved global acclaim for being the first to ever person like him to ever direct a full-length dance play.

These people cannot lose their Down syndrome. They can’t be cured of it. But it doesn’t get worse, which means they can go on to achieve more things in their lives. They’re just unique individuals with a unique genetic marker.

How Can Someone Live With Trisomy 21? Growing Up with Down Syndrome

With love, education, and support. That’s how.

Madeline and Chris are only two examples. In 2024, Rachel High became the first known Australian to earn a Bachelor’s Degree. It took her 10 years, but she did it. Outside Australia, Mar Galcerán’s story inspires everyone, including regular people. Despite living with Down syndrome, she joined Spanish politics at 18, participated actively, led protests and discussions, and in January 2024, at the age of 45, she got elected to Valencia’s parliament, representing her people.

There are even stories of parents with Down syndrome. This isn’t normally medically advisable, but there are stories. People with the condition have achieved, are achieving and will achieve.

And all of these successes were catalysed by regular people. It all started with early detection (for some) and a decision to support them (for all). Modern medicine did its bit by finding ways to increase their life expectancy from late teens to early 30s, into their 60s. The rest came from a deliberateness on the part of those who support them.

Send them to the right schools that have learning programmes socially tailored for special children. Throwing them into a school for regular children will make matters worse for them. They can even get depressed. Get them speech therapists and find them a community of people like them where they can learn social skills. If any of these will cost more than you can afford, turn to the National Disability Insurance Scheme (NDIS) for support.

The NDIS even provides funding for job training for the older ones. This training also places them in jobs where they can learn at their own pace until they are able to keep up.

Nobody is asking, “What is Down syndrome?” or “What can’t people with Down syndrome do?”. Everybody is asking, “How can we help them do what they love?” instead, which shows a gradual shift to a more supportive mindset towards people living with the condition.

If any of these things threaten to overwhelm you, reach out to Support Network. We will be your safety net and provide everything you need to help your loved one have a full life while living with the condition.

Practical Tips to Support a Person With Down Syndrome

With the Down syndrome definition out of the way, Trisomy 21 explained, and real-life examples of people living with the condition who have done stellar things in their lives thanks to the right support shared, it’s time for you to learn how to support them.

Here are practical tips to support a person living with Down syndrome.

1. Check out the NDIS

The government has given us the NDIS to help all disabled people live quality lives. Even if you can afford to pay for care, you should check out what the NDIS has to offer. They’re not just for funding. They offer programmes that can help your child/ward live the life they deserve.

2. Don’t wait after diagnosis

Once you confirm that your child or ward has Down syndrome, immediately set to work on finding support services and evidence‑based early intervention programs (speech therapy, occupational therapy, physiotherapy) before school age. With these, you can lay a good foundation for their learning to go more smoothly than it typically would have.

3. Get an Individualised Education Plan (IEP)

The best thing is to send them to special schools that cater to their needs. However, if you can’t for financial or location reasons, let their teachers at their schools know. Then, work with them to co‑design an IEP or Learning and Support Plan (LaSP) in line with the Australian Curriculum. Do this in conjunction with allied health staff. Make sure you include specific literacy, numeracy, and life skills targets that these teachers will help them meet.

4. Use plain English and visuals

Do not try to use baby talk when you want to speak with them. Speak to them normally. Speak to them clearly. You might have to speak slowly, but with time, you can have regular conversations with them. Where necessary, use pictures and diagrams to explain things. There are apps that you can use, too.

5. Build functional communication

Some people living with Down syndrome struggle to pick up language. There are tools called AAC (Augmentative and Alternative Communication) tools that can easily help with this. Employ and deploy them if your child/ward is finding it difficult to pick up or understand language. Sign language works just as well for this challenge, too.

6. Build a routine

Like many people with special needs, a consistent routine helps people with Down syndrome. Let them wake up knowing that there is a set day ahead of them, especially in their earliest formative days. It can help them settle into daily living and even start to create their own routines from there.

7. Take regular health screenings and preventative care seriously

This goes without saying. There are specific issues that people living with this condition are more prone to. Visit the doctor regularly to check for these conditions. If you’re confused, follow the Down Syndrome Medical Interest Group Australia’s guidelines. Don’t forget to monitor their mental health as well.

8. Let them play

There are local disability‑inclusive playgroups everywhere, some of them funded by the NDIS. Sign them up for these playgroups so that they can make friends and learn how to interact with others.

9. Let them do things around the house

Don’t leave them out of house chores. Give them chores that they can handle at their current cognitive level. Use it to develop their self-esteem and independence. If their learning rate is much slower, you can show them how to do these things step by step until they learn.

10. Get them to exercise or do sports

Exercise works just as well as anything when it comes to taking care of the human body. The same is true for the very different bodies of people living with Down Syndrome. Even if you can’t find a special sports team or an exercise club for them to join, just having them join you in simple workouts is enough.

11. Plan for their future

When they reach 10 years old, start looking into their futures. What will they do after school? What kind of work can they do? Do they need more physical, speech, occupational therapy or the like? Reach out to any Disability Employment Services to find out what’s possible.

12. Teach them financial literacy and banking

Don’t forget to teach them basic money skills. Let them know the value of fiat, of coins, of goods and services, savings, compounding, and investments. Many Australian banks have evolved to offer accessible banking tools for people with special needs. Take advantage of them so that you can build their financial futures.

13. Locate local support networks

Wherever you and your special child(ren) are, make sure that they have a reliable support network. This is different from the playgroups. Some playgroups may even be an extension of these support networks. State‑based Down syndrome organisations are always a great place to start. You should also join one of these as a parent or guardian, so that you can find peace in the midst of the storm that taking care of someone with Down syndrome can sometimes become.

14. Transport and mobility

There are special reservations to help special people move around Australia. Find them and apply for them.

These 14 tips are exhaustive when applied. They cover every base you can think of when it comes to Down syndrome care. When you use them to create your care plans, make sure to regularly review them every 6–12 months and adapt.

Always celebrate their wins, too. The day they successfully write a full sentence without help, throw a party if you can afford to. This spurs them to do more, and with time, achievement will become regular to them.

Most importantly, stay informed. Read Support Network’s Down syndrome guide for more information on managing this condition and making the most of its. Subscribe to newsletters from Down Syndrome Australia as well, and read up on what advocacy bodies are doing to remain up to date on programs, research, and rights.

Support and Resources

The following resources can help you get started:

• NDIS funding: The secret is in the name. Down syndrome is a kind of disability, and so, there is funding available for treatment and therapies to help them live quality lives, starting from as young as 9 years old.
• State and national associations: Down Syndrome Australia and its state bodies will readily counsel you and help you find playgroups (some of which they sponsor), resources and medical care for your child/ward. Other services like Healthdirect can provide online resources that you can read.

Support Network: We provide trusted support workers to help you achieve your goals for your loved ones with Down syndrome. We also have an online resource filled with information to help you make sense of everything.

Conclusion

In this guide, you have learned why you should move on from asking, “What is Down syndrome?” and worrying if it is your fault, to know all about the condition (Trisomy 21 explained) and how to manage it.

It will overwhelm you sometimes, but that’s why Support Network exists. We stand in the gas to ensure that you’re not running this race alone. Reach out to us to help you come up with a foolproof plan to make the life of your loved one better.

Never forget that we’re always cheering you on!