Genetics Home > Mosaic Turner Syndrome
A woman with Turner syndrome will have one of three possible X chromosome problems, one of which is called mosaic Turner syndrome, or the absence of the X chromosome in some cells. This type of Turner syndrome may result milder symptoms than other types of the disorder. In order to diagnose mosaic Turner syndrome, healthcare professionals may examine blood cells and/or skin cells.
The cause of Turner syndrome is a problem with one of the two X chromosomes (sex chromosomes).
A woman with Turner syndrome will have one of three X chromosome problems:
- Absence of the X chromosome in some cells (called mosaic Turner syndrome)
- Absence of the X chromosome in all cells (see X Chromosome Monosomy)
- Defect of the X chromosome in all cells (see Turner Syndrome and X Chromosome Defects).
A sex chromosome may also be lost during early stages of embryonic development, which can result in some cells of the growing body receiving a single X chromosome. This condition is called mosaicism, and the features of mosaic Turner syndrome correlate with the relative percentage of 45,X cells within the body, compared to 46,XX cells.
If only a small percentage of cells have been affected, the signs and symptoms of Turner syndrome may be relatively mild. An example is a woman with mosaic Turner syndrome possibly experiencing regular menstrual cycles until her late 20s, rather than not having any menstrual cycle at all.