TURNER'S SYNDROME: Dictionary Entry and Meaning
 WordNet Dictionary |
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| | Definition: | | [n] a chromosomal disorder in females who have only one X chromosome; marked by dwarfism and heart abnormalities and underdeveloped sex organs |
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| | See Also: | | sex-linked disorder | |
| Biology Dictionary |
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- Turner's syndrome is characterized by short statue, webbing of the neck, triangular face, coarctation of the aorta, dissecting aneyrysm of aorta, amenorrhea (lack of menstruation), lacking secondary sex characteristics and infertility. Genetically affected patients (all female) are mainly monosomy X; occassionally, other genetic makeups could be found.
- A rare genetic disorder (roughly one in every 2,500 liveborn females are affected) caused by the lack of one X chromosome in human females which results in an X0 karyotype instead of the normal XX karyotype. The condition was first described in 1938 by H.H. Turner. Females with this syndrome have normal intelligence (though they may have some learning difficulties in regard to math and spatial relationships), abnormally short stature, retarded/incomplete sexual development and infertility. They may also suffer from heart defects, kidney defects, thyroid problems, hearing loss, and may have other physical abnormalities. The "classic" physical symptoms of Turner's include puffy hands and feet soon after birth, webbing of the neck, unusually broad chest, and small nipples.
The severity of the disorder may vary widely from person to person, because 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 karyotype throughout all the cells in her body. Infants with the syndrome may have difficulty feeding (due to hard palate deformities) and may show "failure to thrive." Girls with Turner's may experience a partial-to-complete lack of sexual development at puberty; they can be treated with female hormones (estrogen) that can help them develop breasts and other secondary sexual characteristics. Growth hormones treatments are used to improve the girls' heigh (the success of this treatment varies). For more information, visit the Turner's Syndrome Society of the U.S.
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| | Synonyms: | | Bonnevie-Ullrich syndrome, gonadal disgenesis, monosomy X, ovarian dwarfism, pterygolymphangiectasia, Turner-Varny Syndrome, X0 |
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| Glossary |
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| | Definition: | | a genetic disease characterized by forty-five chromosomes with a sex chromosome count of X-; phenotypically female, but sterile. |
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