Turner syndrome (TS), which is also known as Ullrich-Turner syndrome, is a genetic disorder affecting females due to a lack of one functional X chromosome between the normal pair. The chromosome in question may be completely absent or only partially present.
The genotype of TS is 45 XO rather than 46 XX, as one of the X chromosomes is missing. The symptoms of TS are quite varied, with some cases being so severe that they can be diagnosed at birth, whereas some females with TS are diagnosed only when they fail to conceive in adult life.
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Appearance at birth
Baby girls with TS often have extra skin over the neck because they have cystic malformations of the lymphatic tissue under the skin in this region. The skin here may appear webbed. Additional physical characteristics of TS include a hairline that is also abnormally low, the ears are low-set, swollen hands and feet, and soft nails.
Growth and maturation profile
Children with TS grow slowly and their adult height is shorter than usual. Puberty is typically absent, as the ovaries fail to develop properly, thus leading to a lack of reproductive capability.
TS is associated with major anomalies of the heart and blood vessels, as well as a high incidence of hypertension (40% in adult life). Some congenital heart problems associated with TS include coarctation of the aorta and a bicuspid aortic valve. Mitral valve prolapse, ischemic heart disease, and arteriosclerosis are other acquired problems.
In some women with TS, the kidneys are abnormal. Additionally, a lack of normal estrogen leads to weak bones, fracture risk, and loss of height. TS is also associated with a high risk of type 2 diabetes and hypothyroidism.
Most females with TS have normal intelligence capabilities; however, TS is associated with certain neurologic and psychological problems. To this end, TS patients can experience visuospatial incoordination, which causes the affected individual to find it difficult to locate objects in the space around her by sight, as well as difficulties with abstract thinking. Verbal skills are typically intact or superior as compared to non-TS girls.
What is Turner Syndrome? (HealthSketch)
Diagnosis and Management
TS occurs in about 1 in 2,500 female liveborn children, and no known environmental factor is to blame. It is not heritable.
The diagnosis of TS may be made on the basis of the symptoms and physical findings and confirmed by a karyotype test, in which the chromosomes are examined under a microscope to detect if any are missing or abnormal.
Treatment is symptomatic and can involve the use of human growth hormone if TS is detected in childhood to increase the final adult height. Estrogen therapy in adolescence is necessary to mimic the secondary sexual development in normal puberty, such as breast development, but cannot bring about fertility without assisted reproduction.
Combined estrogen and progesterone therapy may help to achieve menstruation, and the estrogen also helps protect against osteoporosis. Psychosocial therapy focused on helping the child cope with social and vocational demands, as well as dealing with self-esteem and cognitive issues is helpful. Regular monitoring for other heart and endocrine problems, for instance, is essential.