title: The frequency and spectrum of K-ras mutations among Iraqi patients with sporadic colorectal carcinoma.
abstract: BACKGROUND
  The epidemiology of colorectal cancers (CRC) is well known to differ in different geographical regions. K-ras mutations have been implicated in CRC carcinogenesis and they were extensively studied in developed countries; however, such studies are scarce from developing countries, like Iraq.
  
  
  OBJECTIVE
  To determine the frequency and spectrum of K-ras mutations among CRC Iraqi patients, and their clinico-pathological associations, if any.
  
  
  METHODS
  Fifty consecutive surgically resected sporadic CRC were evaluated. The evaluation included screening for ten K-ras mutations in codon 12 and 13 by mutant enriched polymerase chain reaction followed by reverse hybridization to oligospecific probes.
  
  
  RESULTS
  Out of the 50 enrolled patients, 24 (48%) had K-ras mutations. A total of 29 mutations were identified in the tumors of the latter 24 patients (20/24 tumors had single mutations, 3/24 had double mutations and 1/24 had triple mutations). The most frequently encountered mutations were the G>T transversions and G>A transitions (41.4% each). Codon 12 mutations constituted 89.7%, while codon 13 the remaining 10.3%. The most frequent mutation was GGT>GTT (Gly>Val) of codon 12 documented in 31%. No significant clinico-pathological correlations with K-ras mutational status were identified.
  
  
  CONCLUSIONS
  The K-ras mutations are frequently encountered among Iraqi sporadic CRC patients, with relative higher frequencies of G>T transversions and Gly>Val codon 12 substitutions than encountered in their counterparts in developed countries. The latter is most likely to be related to differences in local carcinogens exposure, an aspect which requires further scrutiny.
authors: Department of Pathology, College of Medicine, University of Dohuk, Dohuk, Iraq.
authors: N A
authors: NA
authors: Al-Allawi
authors: A T
authors: AT
authors: Ismaeel
authors: N Y
authors: NY
authors: Ahmed
authors: N S
authors: NS
authors: Merza
mesh_terms: D000328:Adult; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007493:Iraq; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins