fragile site


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frag·ile site

[MIM*136540, MIM*136670]
a nonstaining gap at a specific point on a chromosome, usually involving both chromatids, always at the same point on chromosomes of different cells from an individual or kindred; it results in in vitro production of acentric fragments, deleted chromosomes, or other chromosome anomalies; inherited as a dominant chromosome marker.

frag·ile site

(fraj'il sīt)
A nonstaining gap at a specific point on a chromosome, usually involving both chromatids, always at the same point on chromosomes of different cells from an individual or kindred.

fragile site

a site in a CHROMOSOME where breakage is likely to occur due to the presence of an expanded trinucleotide repeat (see TRINUCLEOTIDE REPEAT EXPANSION DISEASE).
References in periodicals archive ?
Chromosomal fragile sites expressed through an increased frequency in gaps and breaks are identified, as well as a presence of conservation of fragile sites throughout evolution [13, 14].
Eleven affected males and one carrier female were found to have a fragile site on the X chromosome (fra(X)(q27)).
Although the exact mechanism of fragile site expression still remains unclear, however some external factors have been implicated to be instrumental for their expression.
The underlying DNA structure of fragile sites appears to make them particularly prone to breakage and hence to being jettisoned from the cancer genome.
Population cytogenetics of folate-sensitive fragile sites.
Folate sensitive fragile site expression seems to appear as a result of heritable defects of DNA methylation along a region normally binding a folding protein involved in chromosome condensation.
Although only a small fraction of the wall and its forts has been excavated, the fragile site is being eroded by heavy boots, say archaeologists.
It's exciting,'' said Parks, who is fighting to locate the dam on a less environmentally fragile site.
A candidate gene for mild mental handicap at the FRAXE fragile site.
In deference to the fragile site, the building is raised above the ground on columns, permitting drainage and vegetation to continue uninterrupted.
It is an extremely sensitive and fragile site," said Brian Mansell, head of the Tasmanian Aboriginal Land Council.
Indeed, one fragile site under suspicion--a long string of DNA on human chromosome 3 called FRA3B--is often disrupted in breast cancer, researchers reported last month in Denver at a meeting of the American Society of Human Genetics.