Biomedical subjects

Ana Osorio

Publications and source records attributed to Ana Osorio.

21 records · Page 2Linked to original sources

PubMed2002

Association between BRCA1 and BRCA2 mutations and cancer phenotype in Spanish breast/ovarian cancer families: implications for genetic testing.

Index cases from a clinically relevant cohort of 102 Spanish families with at least 3 cases of breast and/or ovarian cancer (at least 1 case diagnosed before age 50) in the same lineage were screened for germline mutations in the entire coding sequence and intron boundaries of the breast cancer susceptibility genes BRCA1 and BRCA2. Overall, the prevalence of mutations was 43% in female breast/ovarian cancer families, 15% in female breast cancer families and 100% in male breast cancer families. Three recurrent mutations (185delAG, 589delCT and A1708E) explained 63% of BRCA1-related families. Early age at diagnosis of breast cancer, ovarian cancer, bilateral breast cancer, concomitant breast/ovarian cancer in a single patient and prostate cancer but not unilateral breast cancer were associated with BRCA1 and BRCA2 mutations. Male breast cancer was associated with BRCA2 mutations. The presence of male breast cancer was the only cancer phenotype that distinguished BRCA2- from BRCA1-related families. We have developed a logistic regression model for predicting the probability of harbouring a mutation in either BRCA1 or BRCA2 as a function of the cancer phenotype present in the family. The predictive positive and negative values of this model were 77.4% and 79%, respectively (probability cutoff of 30%). The findings of our work may be a useful tool for increasing the cost-effectiveness of genetic testing in familial cancer clinics.

Age of Onset↗

PubMed2002

Evaluation of linkage of breast cancer to the putative BRCA3 locus on chromosome 13q21 in 128 multiple case families from the Breast Cancer Linkage Consortium.

The known susceptibility genes for breast cancer, including BRCA1 and BRCA2, only account for a minority of the familial aggregation of the disease. A recent study of 77 multiple case breast cancer families from Scandinavia found evidence of linkage between the disease and polymorphic markers on chromosome 13q21. We have evaluated the contribution of this candidate "BRCA3" locus to breast cancer susceptibility in 128 high-risk breast cancer families of Western European ancestry with no identified BRCA1 or BRCA2 mutations. No evidence of linkage was found. The estimated proportion (alpha) of families linked to a susceptibility locus at D13S1308, the location estimated by Kainu et al. [(2000) Proc. Natl. Acad. Sci. USA 97, 9603-9608], was 0 (upper 95% confidence limit 0.13). Adjustment for possible bias due to selection of families on the basis of linkage evidence at BRCA2 did not materially alter this result (alpha = 0, upper 95% confidence limit 0.18). The proportion of linked families reported by Kainu et al. (0.65) is excluded with a high degree of confidence in our dataset [heterogeneity logarithm of odds (HLOD) at alpha = 0.65 was -11.0]. We conclude that, if a susceptibility gene does exist at this locus, it can only account for a small proportion of non-BRCA1/2 families with multiple cases of early-onset breast cancer.

Australia↗

PubMed2002

A rapid and easy method for multiple endocrine neoplasia type 1 mutation detection using conformation-sensitive gel electrophoresis.

Until now, the study of the multiple endocrine neoplasia type 1 (MEN1) gene in patients suspected of having the disease was expensive and laborious due to the large size of the gene. We have optimized the conformation-sensitive gel electrophoresis (CSGE) technique to analyze by four rather simple multiplex PCR reactions, and a single electrophoresis run, the entire coding region of the MEN1 gene, plus the exon-intron boundaries. This improvement of the CSGE technique was confirmed as an effective procedure for screening for the MEN1 gene by detecting ten previously known MEN1 gene mutations and four polymorphisms. The MEN1 gene of 12 patients with unknown mutations was then screened, and an abnormal CSGE profile was identified in 10/12 cases. Subsequent DNA sequencing demonstrated 3 of them to be novel mutations (E45K, 4479delACAG, 6073insC) and 7 to have been previously reported; in the remaining 2 patients, we confirmed the absence of any alteration of the coding sequence of MEN1. Mutation screening of the MEN1 gene using CSGE was demonstrated to be a fast, simple, and inexpensive method to study patients suspected of having MEN1 disease.

Amino Acid Substitution↗