Peutz-Jeghers polyps, dysplasia, and K-ras codon 12 mutations.
BACKGROUND
Peutz-Jeghers syndrome (PJS) is a rare, autosomal dominant, polyposis syndrome, associated with an increased risk of gastrointestinal and extragastrointestinal malignancy. Occasionally dysplasia occurs in PJS polyps.


OBJECTIVE
In colorectal carcinomas, mutations in codon 12 of the K-ras oncogene are common and are found at similar frequency in precursor adenomas. Therefore, K-ras codon 12 point mutations in PJS polyps, were evaluated.


METHODS
Fifty two PJS polyps, including four with dysplasia, collected from 19 patients with PJS, were analysed for mutations in the K-ras codon 12 by a mutant enriched polymerase chain reaction procedure, followed by allele specific oligodeoxynucleotide hybridisation.


RESULTS
A K-ras codon 12 mutation was identified, in one colonic polyp with dysplasia. The mutation was found in the non-neoplasmic epithelial cells and not in the dysplastic component of the polyp.


CONCLUSIONS
K-ras codon 12 point mutations are very rare in PJS polyps, by contrast with colorectal adenomas. The findings support previous evidence that there seems to be no intrinsic relation between K-ras codon 12 mutation and dysplasia.
Entius
M M
MM
Department of Pathology, University of Amsterdam, The Netherlands.
Westerman
A M
AM
Giardiello
F M
FM
van Velthuysen
M L
ML
Polak
M M
MM
Slebos
R J
RJ
Wilson
J H
JH
Hamilton
S R
SR
Offerhaus
G J
GJ
D001345:Autoradiography; D003062:Codon; D011905:Genes, ras; D005998:Glycine / Q000235:genetics; D006801:Humans; D010580:Peutz-Jeghers Syndrome / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D014633:Valine / Q000235:genetics
D003062:Codon; D014633:Valine; D005998:Glycine