Interestingly, several of the miRNAs were located inside fragile sites and/or in the cancer-associated genomic regions.
Human microRNA genes are frequently located at fragile sites and genomic regions involved in cancers.
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
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).
Band 7p22 in patient 1 corresponded to the map location of common fragile sites
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
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 centre, operated by Arizona State University, had to accommodate two very different programmes, one, a warehouse to safely store artifacts and support archival preservation; the other - now becoming the more important - introduces the contemporary visitor to rock art and behaviour at such fragile sites
This kind of intensive recreation should not be the emphasis of a park set aside to protect ancient and fragile sites
, a place that is an outdoor church for the Pueblo Indians," Butcher said.
Seven essays consider such topics as the clinical and molecular genetics of neuro-fibromatosis type I, maternal alkaline phosphatase in Down's syndrome pregnancy, and fragile sites
on medical genetics.
, chromosome regions that are prone to break apart or suffer mutations, appear to be weak links in the chain of events that guides development from embryo to adult.