Is trisomy 21 the same as mosaic?
Doctors and researchers use the term “mosaicism” to describe a mix of cells in the body. While people with the more common trisomy 21 Down syndrome have an extra chromosome in all of their cells, people with mosaic Down syndrome only have the extra chromosome in some cells.
How does mosaic trisomy 21 occur?
Mosaic Down syndrome is caused by a random event shortly after the egg and sperm join together. When cells are dividing, some cells receive an extra copy of chromosome 21. Others do not. People with mosaic Down syndrome have some cells with two and some cells with three copies of chromosome 21.
What is mosaic Downs Syndrome?
When a baby is born with Down syndrome, the healthcare provider takes a blood sample to do a chromosome study. Mosaicism or mosaic Down syndrome is diagnosed when there is a mixture of two types of cells. Some have the usual 46 chromosomes and some have 47.
Can you have mosaic Down syndrome and not know it?
Approximately 1 in 27,000 people are diagnosed with mosaic Down syndrome. Approximately 15% of individuals diagnosed with Trisomy 21 Down syndrome are misdiagnosed and actually have mosaic Down syndrome. There are many individuals who are never diagnosed with this condition.
Can a baby with Down syndrome look normal?
Some of the children with Mosaic Down syndrome that we know do not actually look as if they have Down syndrome – the usual physical features are not obvious. This raises some important and difficult social issues and identity issues for both parents and children, which parents have discussed with us.
What are the signs of mosaic Down syndrome?
Mosaic Down syndrome symptoms
- slower speech.
- lower IQ.
- a flattened face.
- small ears.
- shorter height.
- eyes that tend to slant up.
- white spots on the iris of the eye.
What is the mildest form of Down syndrome?
People with mosaic Down syndrome often, but not always, have fewer symptoms of Down syndrome because some cells are normal.
Can two down syndromes have a normal baby?
Women with Down syndrome are able to have children, but many men with the condition unfortunately are not able to, however it is possible. Women who have Down syndrome are able to have children; they have a 35-50% chance that their baby will have Down syndrome.