Biomedical subjects

Sabine Pages-Berhouet

Publications and source records attributed to Sabine Pages-Berhouet.

3 recordsLinked to original sources

PubMed2004

A high-throughput mutation detection method based on heteroduplex analysis using graft copolymer matrixes: application to Brca1 and Brca2 analysis.

We present here a new approach to electrophoretic heteroduplex analysis (EHDA) based on improved matrixes. EHDA is an appealing technique for the detection of unknown point mutations because of its simplicity and high throughput. We present here a new matrix for electrophoretic heteroduplex analysis much more sensitive for insertions, deletions, and substitutions than reported for previous EHDA separations and also superior to DHPLC. This separation matrix is based on a copolymer with a comb architecture, poly(acrylamide-g-polydimethylacrylamide), made of a high molecular weight polyacrylamide backbone grafted with poly(dimethylacrylamide) side chains. The effect of operational parameters on electrophoretic resolution and sensitivity to single-nucleotide mismatches was studied using a collection of samples from patients bearing mutations in the breast cancer predisposition genes BRCA1 and BRCA2. Seventeen fragments (10 mutations), implying mostly substitutions on fragments with sizes ranging from 200 to 600 bp, were analyzed using a single set of separation conditions. A success rate of 94% was achieved with a qualitative analysis in terms of number of peaks, and 100% identification of mutations was obtained with a more quantitative test using peak width analysis. This strong improvement of performance with regard to previous HDA methods is attributed to a composite mechanism of separation, combining steric and chromatographic effects. It opens the route to a significant reduction of development time and operation cost for diagnostic and genomic applications.

Base Sequence↗

PubMed2004

Fidelity of DNA double-strand break repair in heterozygous cell lines harbouring BRCA1 missense mutations.

Germ-line mutations of the BRCA1 and BRCA2 genes, when they lead to a truncated protein, confer a high risk of breast and ovarian cancer. However, the role of BRCA1 missense mutations in cancer predisposition is unclear. Functional assays may be very helpful to more clearly define the biological effect of these mutations, and could therefore be useful in clinical practice. A recent study using a Host Cell End-Joining assay showed that a truncating mutation results in impaired fidelity of DSB repair by DNA end-joining. In the present study, we examined the fidelity of DSB repair in four lymphoblastoid cell lines with BRCA1 missense mutations. The fidelity of DNA end-joining was impaired in the four cell lines studied compared to the normal control cell line. The fidelity of end-joining was similar to that of a truncated mutation control cell line for one cell line and slightly higher for the other cell lines.

Cell Line↗

PubMed2003

Characterisation of a 161 kb deletion extending from the NBR1 to the BRCA1 genes in a French breast-ovarian cancer family.

A large germline deletion removing exons 1 to 22 of the BRCA1 gene has been previously detected using quantitative PCR based methods (QMPSF and real time PCR gene dosage assay) in a woman affected with breast and ovarian cancer. Here, we report its characterisation by using colour bar code on combed DNA of the BRCA1 region. The 5' boundary is located in a Alu Y sequence in NBR1 intron 18 whereas the 3' boundary is located in a Alu Sc sequence in BRCA1 intron 22. This 161 kb deletion encompassing the NBR1, PsiBRCA1, NBR2 and BRCA1 genes is the largest BRCA1 deletion reported so far. No specific phenotype was associated with the hemizygosity of these four genes.

BRCA1 Protein↗