Trisomy 21
Down syndrome
Each cell of our body contains 23 pairs of chromosomes. However, anomalies can occur during conception. In the case of trisomy 21, also known as Down syndrome, an extra chromosome is added to the 21st pair of chromosomes. Trisomy 21 is usually not inherited and occurs randomly.
Screening and diagnosis
There are screening tests that can estimate the risk that the fetus has trisomy 21. Results are usually obtained through an ultrasound (nuchal translucency) and a blood test, generally performed before the 14th week of pregnancy. Screening can also be done using a genetic test or certain diagnostic procedures (e.g., amniocentesis). In some cases, the diagnosis is made only at birth. These tests are offered on a voluntary basis, after discussion with the care team overseeing the pregnancy.
Characteristic features
The characteristic physical features of people with Down syndrome are as follows:
- Less prominent facial profile
- Slightly slanted eyes
- Low nasal bridge
- Prominent tongue
- Small ears
- Small hands
- Short neck
- Shorter-than-average stature
Trisomy 21 may also be associated with certain complications, including:
- Heart problems
- Digestive system problems
- Vision or hearing problems
- Respiratory problems
- Learning difficulties
Care and development
Different therapies can improve the quality of life and help people living with Down syndrome to become more independent (e.g., speech therapy, physiotherapy, or occupational therapy).
With support and ongoing stimulation from an early age, they can attend school and pursue a career.
Thanks to therapeutic advances in recent years and the prevention of complications, people with trisomy 21 can expect to live beyond the age of 60.