Trisomy facts for kids

A trisomy happens when a person has three copies of a chromosome instead of the usual two. Humans normally have two copies of each chromosome in their cells. Having an extra chromosome can change how a person grows and develops.

What is a Trisomy?

Our bodies are made of tiny building blocks called cells. Inside each cell are structures called chromosomes. Chromosomes carry all the instructions, called genes, that tell our bodies how to grow and work. Most people have 23 pairs of chromosomes, making a total of 46 chromosomes. One chromosome from each pair comes from your mother, and the other comes from your father.

When a trisomy occurs, it means there's an extra copy of one specific chromosome. So, instead of a pair (two copies), there are three copies of that chromosome. This extra genetic material can affect how the body and brain develop.

Down Syndrome: A Common Trisomy

The most well-known type of trisomy is called Trisomy 21. This is much more commonly known as Down syndrome. In Down syndrome, a person has three copies of chromosome number 21, instead of two.

How Does Down Syndrome Affect People?

Down syndrome is a genetic disorder that affects a person's development. People with Down syndrome often have some unique physical features. They may also have some level of intellectual disability, meaning they learn and develop at a slower pace.

It's important to remember that every person with Down syndrome is unique. They have their own personalities, talents, and abilities. Many people with Down syndrome live full and happy lives, go to school, work, and contribute to their communities.

Other Types of Trisomy

While Trisomy 21 (Down syndrome) is the most common, other trisomies can happen. These are usually much rarer and often have more severe health challenges. Some examples include:

• Trisomy 18 (also known as Edwards syndrome)
• Trisomy 13 (also known as Patau syndrome)

These conditions are often associated with serious health problems and can be very challenging for affected individuals and their families.

Images for kids

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  Karyotype of a human with Trisomy 21 (Down syndrome)