Value of bilateral breast cancer for identification of rare recessive at-risk alleles: evidence for the role of homozygous GEN1 c.2515_2519delAAGTT mutation.

Virtually all known tumor predisposing genes have been identified via the analysis of familial cancer cases. Here we argue that this approach is likely to miss recessively acting cancer genes and suggest the analysis of family history-negative patients with multiple primary malignancies for identifying homozygous at-risk genotypes. We performed calculations showing that the homozygous carriers of rare recessive cancer predisposing alleles are unlikely to report a family history of the disease.

[The gastrointestinal stromal tumor of the stomach in child: characteristic of diagnostics].

The observation of stromal gastric tumor of 12 years old girl has been investigated. The diagnostics was carried out on tumor biopsy taken by a laparoscopy. An evident edema of stroma caused "pseudo-papillary" organization of epithelioid cell neoplasm prevented the right diagnosis established only by immunohistochemical staining of CD117 and CD34 markers.

KIT mutations in Russian patients with mucosal melanoma.

A single institution series of 48 mucosal melanomas (MMs) has been analyzed for the presence of KIT mutations using high-resolution melting and sequencing of abnormally melted DNA fragments. The analysis of exons 9, 11, 13, and 17 has revealed eight of 48 (17%) nonsynonymous alterations, including zero of seven head and neck, six of 24 anorectal, one of 15 genitourinary, one of one gastric, and zero of one mediastinal MMs. Seven of these mutations were potentially associated with the tumor sensitivity to KIT tyrosine kinase inhibitors.

High prevalence and breast cancer predisposing role of the BLM c.1642 C>T (Q548X) mutation in Russia.

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.

[Significant regression of glioblastoma with low level of Mgmt gene expression following radiotherapy].

Radiochemotherapy is leading the universal research effort in fighting lethality: it is improving relapse-free survival of patients with inoperable glioblastoma, the most pernicious brain tumor in adults. Its effectiveness was found to depend on expression of Mgmt gene of tumor DNA reparation following radiochemotherapy and adequate medication based on the molecular phenotype of tumor. Our study involved a 40-year old male with a low level of Mgmt gene expression as established by stereotactic biopsy.