(Ullrich)- Turner syndrome (monosomy X)

The incidence of Turner syndrome is 1:2,000 and it only occurs in females. The genetic feature of this syndrome is that it only affects the sex chromosomesThe affected girls and women have only one X chromosome instead of two, and therefore possess only 45 instead of the normal 46 chromosomes. This can manifest itself in a number of very different ways, whereby the physical characteristics are similar to those of the Noonan syndrome. Patients with Turner syndrome have underdeveloped ovaries and are therefore sterile. A number of other organs can also be affected; kidney malformations occur in 25-50 per cent of cases and heart defects are also common, usually in the form of aortic isthmus stenosis. Even more common are defects in the area of the cardiac valve between the left ventricle and the aorta and although this feature may be of no consequence initially, it can acquire medical significance during the course of life. The main cause of death among women with Turner syndrome are diseases or complications associated with the heart or aorta.

Author(s): Dr Stefanie Weismann-Günzler
Reviewed by: Dr Heide Seidel
Last updated: 2014-03-13