Cause of Turner's Syndrome
Turner's Syndrome is caused when one of the female sex chromosomes is either incomplete or missing
- Monosomy. The complete absence of an X chromosome generally occurs because of an error in the father's sperm or in the mother's egg. This results in every cell in the body having only one X chromosome.
- Mosaicism. In some cases, an error occurs in cell division during early stages of fetal development. This results in some cells in the body having two complete copies of the X chromosome. Other cells have only one copy of the X chromosome, or they have one complete and one altered copy.
- Y chromosome material. In a small percentage of Turner syndrome cases, some cells have one copy of the X chromosome and other cells have one copy of the X chromosome and some Y chromosome material. These individuals develop biologically as girls, but the presence of Y chromosome material increases the risk of developing a type of cancer called gonadoblastoma.