Trisomy 13, also called Patau syndrome, happens when a baby is born with an extra copy of chromosome 13. Normally, we have two copies of each chromosome, but with trisomy 13, there are three copies of chromosome 13. This extra genetic material throws off how a baby develops before birth and causes serious health problems. A doctor named Klaus Patau first described this condition back in 1960, and it’s one of the more challenging chromosomal conditions that babies can be born with.
Why Does This Happen?
When researching trisomy 13 information, you’ll find that the extra chromosome usually appears because of a random mistake when the egg or sperm is forming. It’s not something parents do wrong, and in most cases, it doesn’t run in families. Think of it like a copying error that just happens by chance. There are actually three types of trisomy 13. The most common type is full trisomy 13, where every cell in the body has that extra chromosome. Then there’s mosaic trisomy 13, where only some cells have the extra copy. Finally, partial trisomy 13 means just a piece of chromosome 13 got duplicated. If you’re looking for trisomy 13 information, you should know that full trisomy 13 makes up about 80% of cases.
What Does It Look Like?
Babies with trisomy 13 are born with multiple physical differences that can affect different parts of their bodies. How severe these are depending on which type of trisomy 13 they have.
You might notice these physical signs:
- A cleft lip or palate that makes feeding difficult and needs surgery to fix
- Very small eyes or eyes that didn’t form properly, and sometimes one or both eyes might be missing
- Extra fingers or toes, especially on the hands
- Trouble with thinking and learning as they grow
- Lower birth weight and weaker muscles than other babies
Inside the body, there are often problems with:
- The heart, which doesn’t form correctly in about 80% of babies with trisomy 13
- The brain and spine, which might not develop normally
- The kidneys, which can affect how waste is filtered from the body
- The belly area, where organs might push through the abdominal wall
How Is It Diagnosed and Treated?
Doctors can sometimes spot trisomy 13 before your baby is born through screening tests during pregnancy. Tests like amniocentesis or CVS can confirm it by looking at the chromosomes. After birth, doctors usually suspect trisomy 13 based on how the baby looks, then confirm it with a chromosome test. Unfortunately, there’s no cure for trisomy 13. Instead, doctors focus on keeping your baby comfortable and treating specific problems as they come up. This might mean surgery to fix heart problems or a cleft palate, special feeding methods or feeding tubes to make sure your baby gets nutrition, and regular visits with different specialists who can help manage various health issues.
What Can Families Expect?
Trisomy 13 is very serious. Many babies with this condition don’t survive pregnancy or pass away within their first few weeks or months of life. That said, some children do live longer, especially those with the mosaic or partial types. Every child is different, and every family’s experience is unique. What helps most is having a strong medical team, access to palliative care that focuses on comfort, and connecting with other families who really understand what you’re going through. These support networks can make a huge difference as you navigate this journey.