Q97.2: Mosaicism, lines with various numbers of X chromosomes

When beginning its development, every single cell in the body contains a complete blueprint of the body. This blueprint consists of genetic information. The genetic information is encrypted in the chromosomes. Every human cell normally contains 23 chromosome pairs, i.e. a total of 46 chromosomes.

The X chromosome and the Y chromosome determine a person’s biological gender. Men normally have one X chromosome and one Y chromosome. Women normally have 2 X chromosomes.

You are female. There are cells in your body that have different numbers of X chromosomes. You may still have body cells with 2 X chromosomes, for example. Other body cells may, for example, only have 1 X chromosome or 3 X chromosomes at the same time. This is called Mosaic Down syndrome, or mosaicism.

The condition can vary in severity. It is possible to only have a few or very mild symptoms.

You can also have special features in your face, for example. This includes, for example, an extra fold of skin inside the corner of the eye.

You may also have problems with learning or speaking. There may also be mental symptoms. You may also have weaker muscle tone.

You may also have malformations of the bones or ovaries. The ovaries are part of the female genitals. There are two ovaries, one on each side. The ovaries sit low down in the abdomen. Egg cells mature in the ovaries. The egg cells can later develop into a child. The ovaries also produce various messenger substances.