(also known as X0 syndrome, 45X0).
This syndrome was first fully described in 1938 by Dr H Turner. It is due to the inheritance of only a single sex (female) chromosome. So this is a chromosomal condition that only affects the fetal development in females.
Features of Turner Syndrome:
Short stature – starts to become evident around age 5.
Ovaries develop normally at first but egg cells usually die prematurely and the ovarian tissue degenerates before birth.
Affected girls do not usually go through puberty unless they receive hormone therapy. They are infertile.
A very small percentage of females with Turner Syndrome do retain normal ovarian function through young adulthood.
30% of females with Turner Syndrome have webbed necks, low hairline at the back of the neck and swelling of the hands and feet, skeletal abnormalities and kidney problems.
1/3 to 1/2 females with Turner Syndrome are born with heart defects such as coarctation of the aorta, abnormalities of the aortic valve. Complications with these heart defects can be life-threatening.
Intelligence with Turner Syndrome is not usually affected although some may have developmental delay, learning disabilities and behaviour issues. This varies amongst affected individuals.
Unlike Down, Edwards or Patua syndrome, the risk of having a child with Turner syndrome is not related to the age of the mother and there is no apparent incease in the risk of having a further affected pregnancy. There is a birth incidence of 1:5000 but the majority of cases result in miscarriage or are stillborn.