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 ?
Based onSeralini,[16]and Dryginet al,[17] which refers to GM food may lead to chromosome fragile sites in general and may lead to develop the cancer.
Correlated fragile site expression allows the identification of candidate fragile genes involved in immunity and associated with carcinogenesis.
Almost all cases of FXS are caused by the expansion of a CGG repeat in the 5' untranslated region of the fragile X mental retardation gene (FMR-1) (OMIM #309550) at the FRAXA fragile site Xq27.
With respect to cancer, authors suggest that fragile sites are more prone to breakage and chromosomal rearrangements in somatic cells leading to the possible activation of oncogenes or inactivation of tumor suppressor genes related with cancer pathogenesis (8).
Distribution comparison of chromosomal fragile sites grown in control cultures with no FUdR revealed seven fragile bands in Lohi compared to 24 in Suffolk.
Dr Graham Bignell, a lead author on the paper, said: "We analysed almost 750 cancer cell samples for deletions at known tumour suppressor genes and compared them to deletions at known fragile sites.
X-linked mental retardation, macro-orchidism, and the Xq27 fragile site.
Fragile sites are weak genomic points on chromosomes that are involved in chromosomal rearrangements, deletions and reciprocal translocations and are also correlated with points of evolutionary importance involved in the divergence of different species (Yang and Long, 1993; Ronne, 1995; Ruiz-Herrera, 2005).
The 22 articles in the 2007 edition of the annual series summarize recent developments in understanding cell cycle regulation of DNA replication, chromosome fragile sites, the biology of Candida albicans, and transport of sequence-specific RNA interference information between cells.
The final tier includes subtelomeric FISH; comparative genomic hybridization; screening for folate-sensitive fragile sites, 7-dehydro-cholesterol, and the UBE3A gene; and an extended metabolic work-up.
Even cytogenetic diagnosis of index cases can be misleading and false negative or false positive results are not rare, on the contrary, false negatives arise from faulty lymphocyte culture methods and false positives from common fragile sites near the rare one associated with fragile X syndrome at Xq27.