Biomedical subjects

Eva Esteban-Cardeñosa

Publications and source records attributed to Eva Esteban-Cardeñosa.

6 recordsLinked to original sources

PubMed2006

High proportion of novel mutations of BRCA1 and BRCA2 in breast/ovarian cancer patients from Castilla-León (central Spain).

A total of 264 unrelated breast/ovarian cancer patients and 45 healthy individuals with familial antecedents referred for genetic testing were scanned for germ-line mutations in BRCA1 and BRCA2 by conformation-sensitive gel electrophoresis (CSGE) and heteroduplex analysis by capillary array electrophoresis (HA-CAE). We detected 101 distinct mutations (41 in BRCA1 and 60 in BRCA2); ten of them have not been previously reported. These mutations were c.2411_2429dup19, c.2802_2805delCAAA and c.5294A>G (p.E1725E) of BRCA1; and c.667C>T (p.Q147X), c.2683C>T (p.Q819X), c.5344_5347delAATA, c.5578_5579delAA;insT, c.8260_8261insGA, c.744+14C>T and c.8099A>G (p.Y2624C) of BRCA2. Twenty-four different mutations, including seven of the new mutations (five frameshift and two nonsense), were classified as pathogenic. These 24 alterations were found in 39 families (12.6% of all families). A remarkable proportion of deleterious mutations were found in BRCA2: 25 families carried a mutation in BRCA2 (BRCA2+; 64.1%) compared with 14 families BRCA1+ (35.9%). The highest incidences of deleterious mutations were found in families with three or more cases of site-specific breast cancer (BC) (27.4%) and families with BC and ovarian cancer (22.2%). Finally, four recurrent mutations, 3036_3039delACAA, c.5374_5377delTATG of BRCA2, as well as c.5272-1G>A and c.5242C>A (p.A1708E) of BRCA1, accounted for 44% of all of the deleterious mutations.

Breast Neoplasms↗

PubMed2005

Rapid mutation detection in complex genes by heteroduplex analysis with capillary array electrophoresis.

Mutational analysis of large multiexon genes without prevalent mutations is a laborious undertaking that requires the use of a high-throughput scanning technique. The Human Genome Project has enabled the development of powerful techniques for mutation detection in large multiexon genes. We have transferred heteroduplex analysis (HA) by conformation-sensitive gel electrophoresis of the two major breast cancer (BC) predisposing genes, BRCA1 and BRCA2, to a multicapillary DNA sequencer in order to increase the throughput of this technique. This new method that we have called heteroduplex analysis by capillary array electrophoresis (HA-CAE) is based on the use of multiplex-polymerase chain reaction (PCR), different fluorescent labels and HA in a 16-capillary DNA sequencer. To date, a total of 114 different DNA sequence variants (19 insertions/deletions and 95 single-nucleotide substitutions - SNS) of BRCA1 and BRCA2 from 431 unrelated BC families have been successfully detected by HA-CAE. In addition, we have optimized the multiplex-PCR conditions for the colorectal cancer genes MLH1 and MSH2 in order to analyze them by HA-CAE. Both genes have been amplified in 13 multiplex groups, which contain the 35 exons, and their corresponding flanking intronic sequences. MLH1 and MSH2 have been analyzed in nine hereditary nonpolyposis colorectal cancer patients, and we have found six different DNA changes: one complex deletion/insertion mutation in MLH1 exon 19 and another five SNS. Only the complex mutation and one SNS may be classified as cancer-prone mutations. Our experience has revealed that HA-CAE is a simple, fast, reproducible and sensitive method to scan the sequences of complex genes.

Adult↗

PubMed2004

The variant E233G of the RAD51D gene could be a low-penetrance allele in high-risk breast cancer families without BRCA1/2 mutations.

Six SNPs have been detected in the DNA repair genes RAD51C and RAD51D, not previously characterized. The novel variant E233G in RAD51D is more highly represented in high-risk, site-specific, familial breast cancer cases that are not associated with the BRCA1/2 genes, with a frequency of 5.74% (n = 174) compared to a control population (n = 567) and another subset of breast cancer patients (n = 765) with a prevalence of around 2% only (comparison to controls, OR = 2.6, 95% CI 1.12-6.03; p < 0.021). We found that the immunohistochemical profile detected in available tumors from these patients differs slightly from those described in non-BRCA1/2 tumors. Finally, the structural prediction of the putative functional consequence of this change indicates that it can diminish protein stability and structure. This suggests a role for E233G as a low-penetrance susceptibility gene in the specific subgroup of high-risk familial breast cancer cases that are not related to BRCA1/2.

Age of Onset↗

PubMed2004

The breast cancer low-penetrance allele 1100delC in the CHEK2 gene is not present in Spanish familial breast cancer population.

Searching for low-penetrance genes involved in breast cancer susceptibility has been a field of interest in the last few years. Recently, the CHEK 2 gene, involved in DNA damage and replication checkpoints, has been pointed out as a good candidate; moreover, a specific variant in this gene,1100delC, has been found to increase breast cancer susceptibility among familial breast cancer cases not attributable to mutations in BRCA1 or BRCA2 genes. In our present study, we evaluated the role of the 1100delC variant as a susceptibility allele in breast cancer in the Spanish population. However, our results suggest that this variant is absent or very infrequent in our population, making its screening irrelevant from the practical point of view.

Alleles↗

PubMed2003

High-throughput mutation detection method to scan BRCA1 and BRCA2 based on heteroduplex analysis by capillary array electrophoresis.

BACKGROUND: Scanning for mutations in BRCA1 and BRCA2 in a large number of samples is hampered by the large sizes of these genes and the scattering of mutations throughout their coding sequences. Automated capillary electrophoresis has been shown to be a powerful system to detect mutations by either single-strand conformation polymorphism or heteroduplex analysis (HA). METHODS: We investigated the adaptation of gel-based HA of BRCA1 and BRCA2 to a fluorescent multicapillary platform to increase the throughput of this technique. We combined multiplex PCR, three different fluorescent labels, and HA in a 16-capillary DNA sequencer and tested 57 DNA sequence variants (11 insertions/deletions and 46 single-nucleotide changes) of BRCA1 and BRCA2. RESULTS: We detected all 57 DNA changes in a blinded assay, and 2 additional single-nucleotide substitutions (1186 A>G of BRCA1 and 3624 A>G of BRCA2), previously unresolved by conformation-sensitive gel electrophoresis. Furthermore, different DNA changes in the same PCR fragment could be distinguished by their peak patterns. CONCLUSIONS: Capillary-based HA is a fast, efficient, and sensitive method that considerably reduces the amount of "hands-on" time for each sample. By this approach, the entire coding regions of BRCA1 and BRCA2 from two breast cancer patients can be scanned in a single run of 90 min.

Autoanalysis↗

PubMed2003

Mutational analysis of BRCA2 in Spanish breast cancer patients from Castilla-Leon: identification of four novel truncating mutations.

Mutations in BRCA1 and BRCA2 account for approximately 5% of the overall familial risk of breast cancer. We have carried out a mutational analysis of the entire coding sequence of the BRCA2 gene in 150 breast cancer patients from Castilla-Leon by two different methods: Protein Truncation Test (PTT) and Conformation-Sensitive Gel Electrophoresis (CSGE). We have identified 10 distinct truncating mutations of the BRCA2 protein in 17 unrelated patients. Four mutations had not been previously described in any other population: two nonsense, Q2354X and K3083X, and two frameshift deletions, 6126delT and 5374delTATG. Moreover, three further mutations, 1538delAAGA, E1308X and S2219X, had not been reported in Spanish patients until now. Five mutations were recurrent: 3036delACAA, 1538delAAGA, 9538delAA and the novel mutations, 6126delT and 5374delTATG. The most prevalent mutation was 3036delACAA found in four unrelated patients.

Adult↗