Down syndrome, which is diagnosed by routine tests during pregnancy, is a genetic difference that occurs when babies have an extra chromosome in the 21st chromosome pair. This condition, which is only a possibility during pregnancy, becomes clear at birth. In healthy individuals, the number of chromosomes is 46, while in people with Down syndrome it is 47.
The change in the genetic structure that occurs with Down syndrome greatly affects the baby’s future. Since the gene structure cannot change, Down syndrome is permanent and lasts a lifetime.
People with Down syndrome may have a shorter life expectancy than other people. Deaths due to respiratory and heart diseases are also common in childhood. Since the syndrome is genetic, it cannot be eliminated (until a curative treatment is found…), but with developing technologies, social support and activities, people with Down syndrome adapt to life better and more adaptively.
Down syndrome is divided into three types with the following names:
- Trisomy 21
Of these three types, Trisomy 21 is the most common and mosaic Down syndrome is the least common.
How Is Down Syndrome Diagnosed?
The possibility of Down syndrome can be detected by screening and diagnostic tests during pregnancy. Diagnostic tests are more accurate but can be dangerous for mother and baby.
In the screening tests performed on the mother, the nuchal translucency of the baby is measured by ultrasound. If there are signs of a flat neck, the expectant mother is informed that the baby may have Down syndrome. However, it is important to remember that this process, which causes demoralization and anxiety, may not result in a diagnosis of Down syndrome. Indeed, these tests can be used to measure the likelihood of the baby having Down syndrome, but a definitive diagnosis can only be made at birth.
What Causes Down Syndrome?
There is no clear information about the cause of Down syndrome and experts say that many factors can contribute to this difference. However, when some factors are taken into consideration, it is noticeable that pregnancy after the age of 35 carries a risk in this regard. Also, if there is someone with Down syndrome in the family, the likelihood that the baby to be born will also have this difference increases.