Hi everyone! Today I wanted to talk about Tetrasomy X. My oldest daughter is now 6 years old. She got diagnosed with Tetrasomy X when she was 4 years old.

What is Tetrasomy X?

Tetrasomy X (48,XXXX) is a rare chromosomal condition affecting only females, characterized by the presence of two extra X chromosomes (four total instead of two). It causes variable developmental delays, intellectual disabilities, speech difficulties, and distinct facial features. 

How did you find out?

First, let me go back to my pregnancy and all the signs we noticed. Everything with my 1st pregnancy went great until my 3rd trimester. At one of the ultrasounds, the doctors found an irregularity with my daughter’s heart and circulation. They told me she had mild pulmonary stenosis and that we would need to get her into cardiology as soon as she was born to make sure she’s. Then they told me that my the umbilical cord was not giving her enough oxygen, and so they scheduled my c-section at 38 weeks. Everything went great and they said she would just need to be seen every year to check the dilation of the pulmonary valve in her heart.

As she started growing, we started noticing that she was late in all her milestones. She started lifting her head at 3 months, started rotating her body and reaching things at 10 months old, put weight on her arms to lift herself at 11 months, and so on. Her first steps were at 19 months old. We also noticed she bruised easily.

At 3 years old, she had to get her appendix out. It was a very scary situation because at that point in time, she still wasn’t talking, so she couldn’t tell us she was in pain and where it was. We are beyond thankful for our pediatrician for taking the extra time to wait and notice facial signs.

At 4 years old, her doctor called us and told us that she may have a reason for all her delays, that it could be Noonan’s Syndrome, and asked if we wanted to do a genetic test to find out. She had noticed that our daughter has some of the physical features of Noonan’s, such as low set rotated ears, no bridge in the nose, webbed neck, a sunken breastbone, and guess what? Mild pulmonary stenosis was one of the symptoms. After testing we found out that it wasn’t Noonan’s, it was Tetrasomy X.

What did we learn? Our reaction?

A couple weeks later, we went to a genetics appointment, and they gave us all the information. We learned that although Noonan’s and Tetrasomy X are different conditions, chromosome disorders sometimes cause similar physical traits. We also learned that Tetrasomy X is an extremely rare chromosomal condition affecting only females, and estimated to occur in roughly 1 in 50,000 live female births.

I also wanted to point out that no 2 girls with this condition will be alike. This condition is very rare, and the few that I have known about from a Facebook group are very different and have gone through better or worse situations.

Does she need therapies?

She has been in PT since she turned one. That is how we found out she also had low muscle tone. She started speech therapy around 3 and she is still currently working on that. She had started talking at about 4 years old. She now still struggles with tongue placement and some pronunciation.

Does she go to a special school and/or need special help?

We decided to homeschool and it has been the best decision we have made. She also got diagnosed with level 2 autism when she was 5. If she were in the school system, she would be behind. But I have been homeschooling since preschool age, and it has helped tremendously! I know how she learns, and we work at her own pace. We joined Classical Conversations last year, and since it is a lot of repetition and music, it has worked great for her!

Does she do any extracurricular activities? Does she have restrictions?

In the fall, she does cheer. She is not able to hold anyone or catch them, but she can and loves to cheer. She doesn’t really have any restrictions. We of course use common sense. Like we are not going to put her in wrestling or anything dangerous. But we want her to grow just like any other child.

So yeah friends, that has been our experience with Tetrasomy X. It is not easy. It never has been, but we love our daughter with all our hearts and wouldn’t change a thing. She is special in so many ways that it just amazes us. She is the sweetest, most loving and helpful smart little girl, and the best big sister!

If you have any questions, don’t be afraid to reach out. I know it is tough to be a parent, and sometimes even more being a special needs parent. But we are not alone, and that is why I wanted to create this blog.

Until next time !

-LM