Table 3.

Genetic alterations in the 11 hyperplastic polyps

PatientSize (mm)LocationK-ras mutation*Allelic imbalanceMSIFrequency
1H2R12 Asp, 13 AspAI0 of 10
2H2DNIAI0 of 10
3H2DMSI-L1 of 10
4H2SNI0 of 8
5H3SMSI-L2 of 10
6H4A12 Asp, 12 Ser0 of 9
7H2SAI0 of 9
8H2R12 AspMSI-L1 of 10
9H4A12 SerNI0 of 7
10H2AMSI-H3 of 10
11H3SAIMSI-L1 of 7
  • NOTE: A, ascending colon; D, descending colon; S, sigmoid colon; R, rectum; AI, allelic imbalance; 12 Asp, codon 12 aspartic acid; 13 Asp, codon 13 aspartic acid; 12 Ser, codon 12 serine; (−), no mutation or no allelic imbalance; NI, not informative.

  • * Mutations are shown with the number of the codon involved and the new amino acid expected.

  • MSI-H is based on ≥40% of markers with a novel allele when compared with normal tissue. MSI-L is based on >0% but <40% of markers with a novel allele. The number of positive markers out of the total is also indicated.