The prevalence of BRCA1 and BRCA2 germline mutations in high-risk breast cancer patients of Chinese Han nationality: two recurrent mutations were identified.
ABSTRACT To have an overview of the role of BRCA1 and BRCA2 genes among Chinese high-risk breast cancer patients, we analyzed 489 such high-risk breast cancer patients from four breast disease clinical centers in China, by using PCR-DHPLC or SSCP-DNA sequencing analysis. Allelotype analysis was done at five short tandem repeat (STR) markers in or adjacent to BRCA1 on the recurrent mutation carriers. For those analyzed both genes, 8.7% of early-onset breast cancer cases and 12.9% of familial breast cancer cases had a BRCA1 or BRCA2 mutation, as compared with the 26.1% of cases with both early-onset breast cancer and affected relatives. For those reporting malignancy family history other than breast/ovarian cancer, the prevalence of BRCA1/2 mutation is about 20.5%, and it was significantly higher than the patients only with family history of breast/ovarian cancer (P = 0.02). The family history of ovarian cancer (26.7% vs. 11.9%) and stomach cancer (23.8% vs. 11.8%) doubled the incidence of BRCA1/2, but the difference did not reach the statistical significance. Two recurrent mutations in BRCA1, 1100delAT and 5589del8, were identified. The recurrent mutations account for 34.8% BRCA1 mutations in our series. Similar allelotypes were detected in most STR status for those harboring the same mutations. The BRCA1 associated tumors were more likely to exhibit a high tumor grade, negative C-erbB-2/neu status and triple negative (ER, PgR and C-erbB-2/neu negative) status (P < 0.05). We recommended the BRCA1 and BRCA2 genetic analysis could be done for high-risk breast cancer patient in Chinese population, especially for those with both early-onset breast cancer and affected relatives. There may be some degree of shared ancestry for the two recurrent BRCA1 mutations in Chinese.
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ABSTRACT: Denaturing high-performance liquid chromatography (DHPLC) has been described as a suitable method to study DNA polymorphisms. Here, cassava (Manihot esculenta Crantz) fermentation liquor was examined using DHPLC analysis to characterize the bacterial diversity during the fermentation process. GC-clamped amplicons corresponding to a variable region of the bacterial community 16S rDNA were synthesized using polymerase chain reaction (PCR) and then resolved on a base-composition basis using preparative DHPLC. Eluate fractions were collected at random and used as a source of whole community DNA that could be used to determine the bacterial diversity. As a first approach, GC-clamps were removed from the eluted DNA fragments using PCR to avoid the possible bias these clamps could cause during the construction of clone libraries. As a second approach, a clone library of each eluate sample was constructed, preserving the GC-clamps of the DNA fragments. The first approach generated 132 bacterial rDNA sequences with an average size of 200 bp, 45% of which had similarity to unculturable or non-classified bacteria. The second approach produced 194 sequences identified as Proteobacteria (48%), uncultured or non-classified environmental bacteria (40%) and Firmicutes (12%). We detected a remarkably greater bacterial diversity using the first approach than the second approach. The DHPLC-PCR method allowed for the fast and non-laborious detection of a vast bacterial diversity that was associated with cassava fermentation, and we conclude that it is a promising alternative for the characterization of the overall microbial diversity in complex samples.Genetics and molecular research: GMR 01/2014; 13(1):1304-13. DOI:10.4238/2014.February.28.2 · 0.85 Impact Factor
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ABSTRACT: Introduction: An important risk factor for developing breast cancer is a positive family history of breast cancer. In Malaysia, there is no population-based breast screening programme, but the clinical practice guidelines suggest increased surveillance for those with a positive family history ie mammography for those 40 years old and above, breast self-examination and clinical breast examination yearly. Objective: To determine if women with a family history of breast cancer present with earlier stages of disease. Methodology: From Jan 2001 to Dec 2006, 1553 women with breast cancer presenting to the University Malaya, where family history was recorded, were eligible for this study. Women with a first or second degree relative with breast cancer were compared with those who have no family history with regard to their race, age, stage, size and duration of symptoms. The Chi Square test of significance was used for analysis. Results: Out of 1553 patients, 252 (16.2%) were found to have a relative with breast cancer out of which 174 (11.2%) had at least one affected first degree relative. There were no significant difference in the incidence of positive family history between the Malays, Chinese and Indians. 20% below the age of 40 years old had a positive family history compared with 12.6% in women with no family history. (p0.05). The mean size in the group with no family history was 4.4 cm compared to 4.1 cm in the group with family history. There was a significant difference in screen-detected cancers in the women with family history, 10.7% compared with 5.1% of screen-detected cancers in the group without a family history. However there was no difference in the duration of symptoms between the 2 groups - 25.8% in the women without a family history presented after 1 year of symptoms compared with 22.4% in the group with a family history (p>0.05). Conclusion: Having a family history of breast cancer does not appear to have much impact on the health-seeking behavior of women. Even though there were more screen detected cancers, these comprised only 10% of the group with family history. Public education should target women at risk ie with family history to encourage these women to present earlier and to undergo screening for breast cancer.
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ABSTRACT: Objective. More and more evidences demonstrate that androgen receptor (AR), epidermal growth factor receptor (EGFR), and breast cancer susceptibility gene 1 (BRCA1) have unique clinical implications for targeted therapy or prognosis in triple-negative breast cancer (TNBC). Therefore, we conducted a meta-analysis to summarize the possible associations. Methods. We retrieved published articles about AR, EGFR, and BRCA1 in TNBC from PubMed and EMBASE. The analysis was performed with Rev-Man 5.2 software. Results. A total of 38 articles were eligible for the meta-analysis. Our study showed that the expression level of EGFR (OR = 6.88, P < 0.00001) and the prevalence of BRCA1 mutation (RR = 5.26, P < 0.00001) were higher in TNBC than non-TNBC. In contrast, the expression level of AR was lower in TNBC than non-TNBC (OR = 0.07, P < 0.00001). In the subgroup related to EGFR expression, the level of EGFR expression was significantly increased in Asians (OR = 9.60) compared with Caucasians (OR = 5.53) for TNBC patients. Additionally, the prevalence of BRCA1 mutation in Asians (RR = 5.43, P < 0.00001) was higher than that in Caucasians (RR = 5.16, P < 0.00001). Conclusions. The distinct expression of AR and EGFR and the prevalence of BRCA1 mutation indicated that AR, EGFR, and BRCA1 might be unique biomarkers for targeted therapy and prognosis in TNBC.BioMed Research International 01/2015; 2015:357485. DOI:10.1155/2015/357485 · 2.71 Impact Factor