Turner syndrome, also known as gonadal dysgenesis, is a disease that affects only female subjects due to an abnormal chromosome X. The incidence is 1 female born in 2500. In most cases it is caused by the absence of an entire X chromosome in each cell in the body that normally, in female subjects, it has two more rarely are found in mosaic forms (the chromosome is absent only in some cells in others is present in two copies) and forms caused by chromosomal abnormalities such as structural members in one of the two X chromosomes is somehow damaged.

The syndrome occurs in more nuanced forms in those individuals with mosaic or those caused by structural alterations, and is most evident in the forms due to complete monosomy of chromosome X. The clinical manifestations typically include short stature, 1.45 m on average, a shield chest (rib cage wide and flat), short neck, swelling of feet and hands (peripheral lymphedema), poorly developed secondary sexual characteristics due to abnormal ovarian involving a lack of estrogen production. Women with Turner syndrome also have amenorrhea primary (absence of menstruation) or menopause early. Less than 1% is able to procreate. Can be added cardiac complications, renal anomalies, hypertension, increased susceptibility to autoimmune diseases and development of osteoporosis. In some cases there are myopia or strabismus. The syndrome does not involve mental retardation, although deficits were detected visual-motor and visuo-spatial that can cause problems at school, in this sense is of paramount importance that the quality of family and school that the child must be sufficiently supportive and encouraging attitude iperportettivo differently by family, friends and teachers could have uninflluenza negative effect on mental development of the person.

The life expectancy of women with Turner syndrome is not different from the rest of the population. Much can be done to improve quality by working on clinical manifestations of disease. It ‘may be administered somatotropin (growth hormone) to stimulate the development of the height and using a hormone to the 12 years to foster the development of secondary sexual characteristics of women. Through the administration of somatotropin was reached to obtain an increase in the height of 7 / 8 cm. Currently, the problem of infertility can be overcome thanks to the techniques of assisted fertilization. Any complications from heart or kidney should be kept under medical supervision.

Prenatal diagnosis is possible through karyotype analysis by amniocentesis (taking a small amount of amniotic fluid) or CVS (taking of villous chorion, the cells that form the placenta). The newborn with Turner syndrome presents at birth weight and length below average, swelling of hands and feet, skin folds of the neck.
Sometimes, when the manifestations are mild, the diagnosis is reached only once reached puberty when there is primary amenorrhea and short stature. More accurate post-natal diagnosis is possible through the removal of skin cells obtained from skin biopsy.