Turner syndrome is a genetic condition that only affects females. It is a chromosomal abnormality in which all or part of one of the sex chromosomes is absent or has other abnormalities (unaffected humans have 46 chromosomes, of which two are sex chromosomes). In some cases, the chromosome is missing in some cells but not others, a condition referred to as mosaicism or Turner mosaicism
Types of syndrome:
Babies are usually born with 23 pairs of chromosomes. One pair of chromosomes determines the baby's sex. This pair is known as the sex chromosomes. One sex chromosome comes from the father and the other one comes from the mother. The mother’s contribution is always an X chromosome. The father’s contribution can either be an X or a Y chromosome. A baby girl usually has two X chromosomes (XX) and boys have an X and a Y chromosome (XY). The Y chromosome determines ‘maleness’, so if it is missing as in Turner syndrome, the sex of the child will invariably be female. A female with Turner syndrome has part or all of one X chromosome missing. This means the girl has just one complete X chromosome rather than two.
Turner syndrome is a genetic condition caused by abnormal sex chromosomes.
It only affects females who have a missing or incomplete X chromosome.
Turner syndrome may be diagnosed by amniocentesis or chorionic villus sampling during pregnancy.
Often, fetuses with Turner syndrome can be identified by abnormal ultrasound findings (i.e., heart defect, kidney abnormality, cystic hygroma, ascites).
An increased risk of Turner syndrome may also be indicated by abnormal triple or quadruple maternal serum screen. The fetuses diagnosed through positive maternal serum screening are more often found to have a mosaic karyotype than those diagnosed based on ultrasonographic abnormalities, and conversely those with mosaic karyotypes are less likely to have associated ultrasound abnormalities.
Turner syndrome can be diagnosed post natally at any age. Often, it is diagnosed at birth because of heart problems, an unusually wide neck or swelling of the hands and feet. However, it is also common for it to go undiagnosed for several years, typically until the girl reaches the age of puberty/adolescence and she fails to develop properly (the changes associated with puberty do not occur
A test, called a karyotype or a chromosome analysis, analyzes the chromosomal composition of the individual. This is the test of choice to diagnose Turner syndrome.
There is no cure for Turner syndrome, but many of the associated symptoms like short stature, sexual development problems and learning difficulties, can be treated.