title: New monoallelic combination of KRAS gene mutations in codons 12 and 13 in the lung adenocarcinoma.
abstract: OBJECTIVE
  In a retrospective analysis of the prevalence of KRAS mutations in patients with advanced non-small cell lung cancer (NSCLC), we detected a unique and not earlier described case of a double combination of mutations at codons 12 and 13 of the KRAS gene in a patient with lung adenocarcinoma.
  
  
  METHODS
  To determine the molecular characteristics of the infrequent mutation and the mutational status of the KRAS gene in metastatic brain tumors in the same patient, we performed morphological and molecular tests.
  
  
  RESULTS
  Molecular analysis of the nature of the double mutation showed that the unique combination of variants is a monoallelic mutation. This type of changes has not yet been registered in the Catalogue of Somatic Mutations in Cancer database. Molecular assessment of the KRAS mutation status in the brain metastatic site in the same patient, showed no mutations in codons 12 and 13. Moreover, we did not find mutation at exon 19 and 21 of EGFR gene, both in primary tumor as well as in secondary metastatic foci in the brain.
  
  
  CONCLUSIONS
  The presented case shows an example of KRAS gene molecular mosaicism and heterogeneity of lung adenocarcinoma primary and metastatic tumors. Molecular heterogeneity of lung adenocarcinoma tumors can significantly affect eligibility of patients for targeted therapies.
authors.affiliation: Department of Clinical Molecular Biology, Medical University of Bialystok, Bialystok, Poland. charry22@wp.pl
authors.forename: R
authors.initials: R
authors.lastname: Charkiewicz
authors.forename: W
authors.initials: W
authors.lastname: Niklińska
authors.forename: G
authors.initials: G
authors.lastname: Zalewski
authors.forename: A
authors.initials: A
authors.lastname: Charkiewicz
authors.forename: M
authors.initials: M
authors.lastname: Kozlowski
authors.forename: A
authors.initials: A
authors.lastname: Sulewska
authors.forename: L
authors.initials: L
authors.lastname: Chyczewski
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000483:Alleles; D001932:Brain Neoplasms / Q000235:genetics / Q000556:secondary; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D003062:Codon; D066246:ErbB Receptors / Q000235:genetics; D005091:Exons; D011905:Genes, ras; D006579:Heterozygote; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009362:Neoplasm Metastasis; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D014057:Tomography, X-Ray Computed
chemical_list: D003062:Codon; D066246:ErbB Receptors