Turner Syndrome is a monosomic condition in which only one X chromosome is present (XO). Instead of having a set of 44 autosomes + 1 pair of sex chromosomes (either XX or XY), the person has only 44 autosomes + 1 X chromosomes. It happens in about 1 in 5000 female births. The affected females are of a characteristic phenotype e.g sterile, have a short height, low hairline, small finger nails, and poor breast development with the nipples spread a distance apart. .
- ↑ Anthony JF Griffiths et al., 1990, Modern Genetic Analysis, New York : W.H.Freeman, Chapter 8