Fragile X chromosome
An X chromosome with a heritable fragile site associated with a frequent form of mental retardation — the fragile X syndrome. The fragile X chromosome was first sighted by Dr. Herbert A. Lubs in 1969 who termed it the "marker X.". The fragile X is also called FRAXA. It was the first fragile site found on the X chromosome. The fragile X chromosome is due to a trinucleotide repeat sequence (a recurring motif of 3 bases) in the DNA at that spot.

Medical dictionary. 2011.

Look at other dictionaries:

  • Fragile X syndrome — One of the most common causes of inherited mental retardation and neuropsychiatric disease in human beings, affects as many as one in 2000 males and one in 4000 females. The syndrome is also known as FRAXA (the fragile X chromosome itself) and as …   Medical dictionary

  • fragile-X syndrome — ▪ chromosomal disorder       a chromosomal disorder associated with a fragile site on the end of the X chromosome. The major symptom of the syndrome is diminished mental ability, which may range from mild learning impairment to severe… …   Universalium

  • Fragile X syndrome — Classification and external resources Location of FMR1 gene ICD 10 Q99.2 …   Wikipedia

  • fragile-X syndrome — a major genetic disorder caused by a constriction near the end of the long arm of an X chromosome. The fragile X syndrome is second only to Down s syndrome as a cause of mental retardation. Affected males have unusually high foreheads, unbalanced …   Medical dictionary

  • fragile-X syndrome — a major genetic disorder caused by a constriction near the end of the long arm of an X chromosome. The fragile X syndrome is second only to Down s syndrome as a cause of mental retardation. Affected males have unusually high foreheads, unbalanced …   The new mediacal dictionary

  • fragile x syndrome — noun also fragile x Usage: usually capitalized x Etymology: so called from a fragile (partially gapped) site at band Xq 27 of the X chromosome in those affected with the disorder : an X linked inherited disorder that is caused by a genetic… …   Useful english dictionary

  • fragile X syndrome — a widespread form of mental retardation caused by a faulty gene on the X chromosome. [1980 85] * * * …   Universalium

  • fragile X syndrome — noun Medicine an inherited condition of limited intellectual ability, resulting from an X chromosome that is abnormally susceptible to damage …   English new terms dictionary

  • fragile X syndrome — n. med gen a widespread form of mental retardation caused by a faulty gene on the X chromosome • Etymology: 1980–85 …   From formal English to slang

  • fragile X syndrome — noun a hereditary condition in which the X chromosome is easily damaged, causing a wide range of intellectual impairments …   Australian English dictionary

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