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The BLM gene belongs to the RecQ helicase family and has been implicated in the maintenance of genomic stability. Its homozygous germline inactivation causes Bloom syndrome, a severe genetic disorder characterized by growth retardation, impaired fertility and highly elevated cancer risk. We hypothesized that BLM is a candidate gene for breast cancer (BC) predisposition. Sequencing of its entire coding region in 95 genetically enriched Russian BC patients identified two heterozygous carriers of the c.1642 C>T (Q548X) mutation. The extended study revealed this allele in 17/1,498 (1.1%) BC cases vs. 2/1,093 (0.2%) healthy women (p 5 0.004). There was a suggestion that BLM mutations were more common in patients reporting first-degree family history of BC (6/251 (2.4%) vs. 11/1,247 (0.9%), p 5 0.05), early-onset cases (12/762 (1.6%) vs. 5/736 (0.7%), p 5 0.14) and women with bilateral appearance of the disease (2/122 (1.6%) vs. 15/1376 (1.1%), p 5 0.64). None of the BLM-associated BC exhibited somatic loss of heterozygosity at the BLM gene locus. This study demonstrates that BLM Q548X allele is recurrent in Slavic subjects and may be associated with BC risk.Hereditary risk factors are strongly implicated in breast cancer (BC) predisposition. Mutations in BRCA1 and BRCA2 genes account for approximately 15-20% of familial BC clustering among first degree relatives.

Previous studies indicate that founder mutations may play a noticeable role in breast cancer (BC) predisposition in Russia. Here we performed a systematic analysis of eight recurrent mutations in 302 BC cases (St.-Petersburg, Russia), which were selected due to the presence of clinical indicators of hereditary disease (bilaterality and/or early onset (< or =40 years) and/or family history). BC-associated alleles were revealed in 46 (15.2%) women. BRCA1 5382insC mutation was detected in 29 (9.6%) patients, CHEK2 1100delC in 9 (3.0%), BRCA1 4153delA in 3 (1.0%), CHEK2 IVS2+1G>A in 2 (0.7%), and BRCA1 185delAG, BRCA2 6174delT and NBS1 657del5 in 1 (0.3%) patient each. No cases with BRCA1 300T>G (C61G) mutation was identified. The obtained data suggest that a significant fraction of hereditary BC cases in Russia can be diagnosed using only a limited number of simple PCR tests.

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BACKGROUND:Although the molecular analysis of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) in archived lung cancer tissues is relatively well established, the genetic testing of cytological material has not yet become a routine. METHODS: The current study used cell samples that were obtained by bronchial brushing, transthoracic needle aspiration, or biopsy imprint preparation between 1993 and 2008. Islets of malignant cells were visually located on the archived cytological slides, lysed in situ by a drop of sodium dodecyl sulfate-containing buffer, and subjected to the standard DNA and RNA extraction. Examination of paraffin-embedded tissue blocks (resection specimens or biopsy material) from the same patients was performed in parallel. RESULTS: A total of 75 cytological/histological lung adenocarcinoma sample pairs underwent polymerase chain reaction analysis for the EGFR mutation. Two cytological samples and 1 morphological sample failed to produce DNA. Concordance for the wild-type and mutation status was observed in 54 of 72 and 14 of 72 informative pairs, respectively; 3 pairs and 1 pair, respectively, had mutation only in the cytological or histological material. The discrepancies could be explained by the failure to ensure a high percentage of lung cancer cells in the analyzed samples or, alternatively, by the genuine intratumoral molecular heterogeneity of some neoplasms. RNA extraction followed by reverse transcriptase-polymerase chain reaction analysis for the EML4-ALK translocation was performed for 44 EGFR mutation-negative sample pairs; failures were observed for 2 cytological and 6 histological specimens. All informative pairs were concordant either for the norm (32 of 36 pairs) or for the presence of EML4-ALK gene fusion (4 of 36 pairs). CONCLUSIONS: Archived cytological slides appear to be well suited both for EGFR and ALK analysis.