Turner's syndrome

Turner's syndrome is a genetic abnormality where the affected individual has only one X chromosome (XO), instead of having XX as a normal female or XY as a normal male. It is named for Henry Turner, a doctor who first described this condition in 1938. 1 in about 2,000 females born have Turner's syndrome.

Individuals with Turner's syndrome physically have the appearance of girls but usually have short stature. Their secondary sex characteristics (breasts, pubic hair) are poorly developed. Ovaries fail to develop properly causing them to be sterile (although their wombs are intact so they can bear children with donated eggs).

Intelligence is normal to slightly reduced although problems with maths and visuo-spatial problems seems to be a common thread.

Abnormalities such as coarctation of the aorta and kidney abnormalities are more common in girls with Turner's.

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Eponymous syndromes metanode

Turner's syndrome: a condition marked by a chromosomal anomaly in phenotypic females with the chief pathognomonic symptoms of absence of ovaries (gonadal agenesis or dysgenesis) and short stature. The basic genetic defect is a missing sex chromosome, so that the total count is 45,X. There are several variants of this syndrome For example, the second X may, though present, be partially deleted. In one variant of the so-called mosaics, some cells of the body are 45,X and some 46,XX. Treatment includes giving female sex hormone at the age of puberty to induce adult appearance and menses. Girls with Turner's syndrome are almost invariably sterile.

Dictionary of Sexology Project: Main Index

The "classic" physical symptoms of Turner's syndrome include puffy hands and feet soon after birth, webbing of the neck, an unusually broad chest, and small nipples.

The severity of Turner's syndrome may vary widely from individual to individual, because (as mentioned in a previous writeup) many females may be "genetic mosaics". During the course of their early embryonic development, one or more of their differentiating cells lost an X chromosome so that when they were born, some of their cells were missing an X, but the other cells in their bodies were perfectly normal. Presumably, a woman or girl with a higher number of XX cells than X0 cells would have a much less severe version of the syndrome than a woman or girl who was born with the X0 genotype throughout all the cells in her body.

Infants with the syndrome may have difficulty suckling (due to hard palate deformities) and may show "failure to thrive." In addition to giving girls with Turner's syndrome estrogen treatments (which can help them develop breasts and other secondary sexual characteristics), they are sometimes given growth hormones to improve their height (the success of this latter treatment varies).