Turner syndrome is a genetic disorder that affects the normal sexual development of female patients. This condition generally affects about 1 in 2,500 females worldwide.
Turner syndrome is caused by chromosomal abnormality or nondisjunction of the X chromosome, which involves failure of a pair of sex chromosomes to separate during the formation of an egg. The affected cells may be missing an entire X chromosome or a part of it. The genes on the X chromosome which are responsible for a majority of the signs and symptoms of Turner syndrome have not yet been identified. However, it has been found that an absence of a copy of the SHOX is most commonly responsible for the short stature and skeletal abnormalities in affected individuals.
The symptoms of the condition may vary from one person to another. In some people the symptoms may appear quite early while in some it may appear during or after puberty. Some of the common symptoms include short stature and slow growth rate. At puberty there may be an absence of the secondary sexual characteristics such as initiation of the menstrual cycle or the development of breasts. During infancy the symptoms of turner syndrome include wide or webbed neck, low or indistinct hairline, swollen hands and feet, low set ears, broad chest with widely spaced nipples, presence of cubitus valgus or arms turned outwards at the elbow, delayed growth and below average length at birth. Sometimes the affected girls may also develop cardiac disorders, kidney problems, high blood pressure, and impairment of thyroid gland, learning disability and infertility.
Turner syndrome can be diagnosed at any stage of life. During foetal development a prenatal diagnosis may be helpful to detect any developmental abnormality of the foetus. Ultrasound imaging or other tests such as chorionic villus sampling and amniocentesis can be used to detect the disorder in the foetal stage. In older girls, the diagnosis includes physical examination and a blood test called karyotype analysis to confirm the chromosomal defect. Other tests such as blood-hormone levels, ECG, MRI of the chest or ultrasound of the reproductive organs and pelvic examination may also be used to diagnose the condition.
Hormone replacement therapy is the most common approach for the management of this condition and includes growth hormone and estrogen therapy. The growth hormone may help patients achieve normal height. Estrogen therapy, given in early puberty, helps in proper sexual development.
In some cases surgery may be employed to remove the ovaries of the affected girl to avoid the risk of developing cancer.