April 11, 2025

What is Trisomy 21? Understanding Down Syndrome and Its Impact

What is Trisomy 21?

Each cell in our body has 46 chromosomes that carry instructions for how we grow and develop.

Trisomy 21, also known as Down syndrome, is a condition that happens when a baby is born with an extra copy of chromosome 21.

This extra copy affects fetal development by changing the way cells grow and function.

 


What Causes Trisomy 21?

Trisomy 21 happens by chance when a baby is developing. It is not caused by anything a parent does before or during pregnancy and is not usually inherited. Anyone can have a baby with Trisomy 21, but the chance is higher if the mother is age 35 or older at delivery ¹.

 

What Are the Signs of Trisomy 21?

Babies born with Trisomy 21 may have changes in brain development which can cause mild to moderate intellectual disabilities and delayed development. The physical symptoms of Down syndrome are different in each person.

While some only have the common physical signs, others may have other birth defects or health conditions. These other conditions most commonly include ¹:

  • Hearing loss
  • Sleep apnea
  • Ear infections
  • Eye diseases
  • Congenital heart defects
  • Digestive problems
  • Problems with the upper part of the spine
  • Obesity

Individuals with Down syndrome each have their own unique strengths, talents, and potential. With the right support and opportunities, they can thrive and lead fulfilling, meaningful lives.

 

How Can You Get Tested?

HNL Lab Medicine offers a simple and safe blood test called Noninvasive Prenatal Screening (NIPS). This screening test checks for Trisomy 21 and other conditions as early as 10 weeks into pregnancy. Some other benefits include:

  • Safe – Just a blood test, no risk to the baby
  • Accurate – Helps parents prepare for the future
  • Easy – Done at one of our Patient Service Centers, with results sent directly to your doctor

 

Ask Your Doctor About NIPS

If you are pregnant or planning to be, talk to your doctor about Noninvasive Prenatal Screening. Early testing can help you make informed choices and get the right care.






 

REFERENCE
¹ National Library of Medicine. (2024, January 26). Down Syndrome. National Institutes of Health. https://medlineplus.gov/downsyndrome.html.