Clinical and genetic findings in an Ashkenazi Jewish population with colorectal neoplasms.
BACKGROUND
The authors evaluated the frequency of the carrier status of three ancestral colorectal neoplasm-associated mutations (APC:I1307K, BLM(Ash), and MSH2*1906G>C) found in the Jewish population among a case series with documented colorectal neoplasms. They further compared family and personal histories plus environmental exposures of the carriers and noncarriers of the I1307K mutation and examined clinical differences with regard to the colorectal neoplasms and the specific molecular genetic changes in these lesions.


METHODS
Analyses were performed on tissue from stored paraffin-embedded blocks for the three germline mutations plus the KRAS mutation and APC loss of heterozygosity (LOH) and APC gene sequencing.


RESULTS
Fifty-four of the 429 individuals (12.6%) were found to carry the APC:I1307K mutation, whereas 4 (0.9%) were found to be heterozygous for the BLM(Ash) mutation and 3 (0.7%) were carriers of the MSH21906G>C* mutation. Carriers of the I1307K mutation did not appear to differ from noncarriers with regard to the number of neoplasms, patient age at detection, or tumor location within the colon. There was no significant difference noted between I1307K carriers and noncarriers with regard to the percentage of patients with first-degree relatives with colorectal carcinoma. A significant risk for APC LOH was found in lesions from carriers who smoked cigarettes compared with nonsmokers. The I1307K mutation was found to be clearly associated with a somatic additional adenine insertion in the region of codons 1306-1309, but other mutations in the region of codons 1277-1348 were found to be no more prevalent in carriers than in noncarriers.


CONCLUSIONS
In Jewish individuals previously diagnosed with a colorectal neoplasm, MSH2*1906G>C is uncommon but has been associated with carcinoma occurring at a young age. The BLM(Ash) mutation is uncommon and appears to be of little effect. The I1307K mutation is common among Jews who have had colorectal neoplasms, but overall it was found to have little effect clinically in the current study group. There may be a gene-environment interaction between the I1307K mutation and cigarette use.
Zauber
N Peter
NP
Department of Medicine, Saint Barnabas Medical Center, Livingston, New Jersey, USA. pzauber@aol.com
Sabbath-Solitare
Marlene
M
Marotta
Stephen
S
Zauber
Ann G
AG
Foulkes
William
W
Chan
May
M
Turner
Faye
F
Bishop
D Timothy
DT
D000251:Adenosine Triphosphatases / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics*; D004265:DNA Helicases / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D017491:Genes, APC; D020022:Genetic Predisposition to Disease / Q000208:ethnology*; D018095:Germ-Line Mutation; D006801:Humans; D007585:Jews / Q000235:genetics*; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D051718:MutS Homolog 2 Protein; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D053484:RecQ Helicases; D012907:Smoking
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D000251:Adenosine Triphosphatases; C097151:Bloom syndrome protein; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein; D004265:DNA Helicases; D053484:RecQ Helicases