What is Turner Syndrome
Turner syndrome is a chromosomal condition which significantly affects the development span and reproductive capacity of females. Short stature which becomes evident by around the age of 5 is the most common characteristic of Turner syndrome. An early dysfunction of the ovaries, which is known as hypo-function or premature ovarian failure, is also another common feature in this condition. In fact, the majority of the girls with Turner’s syndrome will not reach puberty unless they are under estrogen hormonal replacement therapy and most out of them will still suffer from infertility later in life. However, there can be a minority of females who will be fortunate enough to retain the normal ovarian function even if the disease condition has affected other parts of the body.
Other Features of Turner syndrome
- Webbed neck (extra folds of skin on the neck)
- Low hairline at the back of the neck
- Lymphedema (swelling of hands and feet)
- Renal problems
- Skeletal abnormalities
- Heart defects – coarctation of the aorta
- Non-verbal learning disabilities
- Behavioral issues
What is the Genetic Pattern of Turner Syndrome
Turner syndrome is chromosomal condition associated with the X chromosome. X and Y are two sex chromosomes present in human body. Females inherit two X chromosomes whereas males inherit one X chromosome and one Y chromosome.
Turner’s syndrome occurs as a result of the absence or structural alteration of one sex chromosome in females. This missing or abnormal particular chromosome will affect the development of the individual, before as well as the after the birth, resulting in a developmental dysfunction.
45,X karyotype, showing an unpaired X at the lower right
- Monosomy X
Nearly half of the individuals with Turner’s syndrome experience this genetic variation where each cell in the body will have only one copy of the X chromosome instead of the normal sex chromosomes present in pairs.
- Partially Missing or Structurally Rearranged Mosaicism
There is a minority of women affected by Turner’s syndrome whose entire chromosome has been affected by a certain abnormality, but only some cells of the body would show the resultant changes. Turner syndrome caused this way is referred to as MosaicTurner syndrome.
Is Turner Syndrome Inherited
Most cases of Turner syndrome are not inherited. In fact, when monosomy X is the particular chromosomal abnormality, it will be precipitated by an event occurring during the formation of eggs and sperms in the parental system. A non-disjunctional error during the cell division can result in an abnormal number of chromosomes.
If one of these abnormal reproductive cells play a role in deciding the genetic makeup of the fetus, it will more or less present a single healthy chromosome in the body with an absent or structurally altered second one, giving rise to features of Turner’s syndrome.
Image Courtesy:
“45, X” By The cat~commonswiki assumed (based on copyright claims). Own work assumed (based on copyright claims). (CC BY-SA 3.0) via Commons Wikimedia
