Distinct BRCA1 rearrangements involving the BRCA1 pseudogene suggest the existence of a recombination hot spot.
Puget N1, Gad S, Perrin-Vidoz L, Sinilnikova OM, Stoppa-Lyonnet D, Lenoir GM, Mazoyer S.
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The 5′ end of the breast and ovarian cancer-susceptibility gene BRCA1 has previously been shown to lie within a duplicated region of chromosome band 17q21. The duplicated region contains BRCA1 exons 1A, 1B, and 2 and their surrounding introns; as a result, a BRCA1 pseudogene (PsiBRCA1) lies upstream of BRCA1. However, the sequence of this segment remained essentially unknown. We needed this information to investigate at the nucleotide level the germline deletions comprising BRCA1 exons 1A, 1B, and 2, which we had previously identified in two families with breast and ovarian cancer. We have analyzed the recently deposited nucleotide sequence of the 1.0-Mb region upstream of BRCA1. We found that 14 blocks of homology between the tandemly repeated copies (cumulative length = 11.5 kb) show similarity of 77%-92%. Gaps between blocks result from insertion or deletion, usually of repetitive elements. BRCA1 exon 1A and PsiBRCA1 exon 1A are 44.5 kb apart. In the two families with breast and ovarian cancer mentioned above, distinct homologous recombination events occurred between intron 2 of BRCA1 and intron 2 of PsiBRCA1, leading to 37-kb deletions. Breakpoint junctions were found to be located at close but distinct sites within segments that are 98% identical. The mutant alleles lack the BRCA1 promoter and harbor a chimeric gene consisting of PsiBRCA1 exons 1A, 1B, and 2, which lacks the initiation codon, fused to BRCA1 exons 3-24. Thus, we report a new mutational mechanism for the BRCA1 gene. The presence of a large region homologous to BRCA1 on the same chromosome appears to constitute a hot spot for recombination.

We know that BRCA1 and BRCA2 are promoters for a Lyncet early-onset cancer breast cancer and the genetics for those can be found in IHOP as well as pub med Google scholar and Wikipedia of causes for the cancer to form can be found in the link above with respect to the various outside causes an inner causes diseases tobacco obesity and the rest that kid proliferate cancer the adaptation to the BRCA mutation is found in Wikipedia one and two linking we do you have extreme to the proliferation of breast cancer and as a precursor for the kids or the manifest itself the bodily systems be out of Tatian that the mutation a mechanism for the BRCA1 gene can be mutated to recombine to formulate copies that are noncancerous but some engineering some knowledge of mutations add the identity of the genetics trade board to the exact gene that BRCA1 exhorts written by Gary Skeete


About garyskeete

ASHWORTH MEDICINE-Professional Medical Assisting, Doctor of Science,Legal Assistant Diploma BSc Criminal Justice PhD Computational Neuroscience MD DSC Epigenetics
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