Turner's syndrome

Turner's syndrome
an abnormal congenital condition resulting from a defect on or absence of the second sex chromosome, characterized by retarded growth of the gonads.
[named after Henry Hubert Turner (1892-1970), U.S endocrinologist, who described it in 1938]

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also called  Gonadal Dysgenesis,  

      relatively uncommon sex-chromosome (sex chromosome) disorder that causes aberrant sexual development in human females. Affected individuals evidence the following signs and symptoms: low hairline; webbed neck; shield-shaped chest with widely spaced nipples; usually kidney and heart malformations with coarctation (narrowing) of the aorta; a 10 percent frequency of moderate to severe mental retardation; (intellectual disability) underdeveloped secondary sex characteristics; and, most importantly, ovarian dysgenesis—i.e., a condition wherein the ovaries are absent or are present only as primitive streaks.

      The disorder sometimes is not recognized until the individual fails to undergo puberty. Treatment with estrogen hormones enables the patient to experience puberty, look mature, and have a normal sex drive. She will remain sterile, however, and malformations (e.g., webbed neck, coarctation of the aorta) can be corrected only by surgery.

      Typically, the body cells of individuals with Turner's syndrome have only one sex chromosome, X, instead of the normal two (XX in females and XY in males). This abnormal chromosomal complement, or karyotype, is designated as 45,X. Turner's syndrome can also arise when only a portion of the body's cells have the 45,X karyotype. Deletion or translocation of part of a sex chromosome can also cause the disorder.

      Turner's syndrome occurs only once in every few thousand female births. Most fetuses with the 45,X karyotype are aborted spontaneously.

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Universalium. 2010.

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Look at other dictionaries:

  • Turner's syndrome — n. a genetic disorder characterized by various deformities and abnormalities; esp., the absence of a female s second X chromosome, which prevents her from maturing sexually …   English World dictionary

  • Turner's syndrome — Tur·ner s syndrome tər nərz or Tur·ner syndrome nər n a genetically determined condition that is typically associated with the presence of only one complete X chromosome and no Y chromosome and with characteristics including a female phenotype,… …   Medical dictionary

  • Turner's syndrome — noun Etymology: Henry Hubert Turner died 1970 American physician Date: 1942 a genetically determined condition that is typically associated with the presence of only one complete X chromosome and no Y chromosome and is characterized especially by …   New Collegiate Dictionary

  • Turner's syndrome — noun Medicine a genetic defect in which affected women have only one X chromosome, causing developmental abnormalities and infertility. Origin 1940s: named after the American physician Henry Hubert Turner …   English new terms dictionary

  • Turner's syndrome — gonadal dysgenesis a genetic defect in women in which there is only one X chromosome instead of the usual two. Affected women are infertile: they have female external genitalia but their ovaries fail to develop normally, resulting in absence of… …   The new mediacal dictionary

  • Turner's syndrome — Tur′ner s syn drome n. pat an abnormal congenital condition resulting from a defect on or absence of the second sex chromosome, characterized by retarded growth of the gonads • Etymology: after Henry Hubert Turner (1892–1970), U.S.… …   From formal English to slang

  • Turner's syndrome — Genetic defect in humans in which there is only one X chromosome (affected individuals are therefore phenotypically female), probably as a result of meiotic non disjunction …   Dictionary of molecular biology

  • Turner’s syndrome — genetic abnormality in females inheriting only forty five chromosomes, causes retarded sexual development …   Eponyms, nicknames, and geographical games

  • Turner's syndrome — noun a chromosomal disorder in females who have only one X chromosome; marked by dwarfism and heart abnormalities and underdeveloped sex organs • Hypernyms: ↑sex linked disorder …   Useful english dictionary

  • Turner syndrome — or Ullrich Turner syndrome encompasses several conditions, of which monosomy X is the most common. It is a chromosomal disorder affecting females in which all or part of one of the X chromosomes is absent. Occurring in 1 out of every 2500 girls,… …   Wikipedia

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