A. Figer et al., Genetic analysis of the APC gene regions involved in attenuated APC phenotype in Israeli patients with early onset and familial colorectal cancer, BR J CANC, 85(4), 2001, pp. 523-526
The genetic basis for the majority of early onset or non-syndromic 'familia
l' colorectal cancer (CRC) is unknown. Attenuated APC phenotype is characte
rized by relatively few colonic polyps, early age at onset of colon cancer
compared with the general population, and inactivating germline mutations w
ithin specific regions of the APC gene. We hypothesized that germline mutat
ions within these APC gene regions, might contribute to early onset or fami
lial CRC susceptibility. To test this notion, we analysed 85 Israeli patien
ts with either early onset (< 50 years at diagnosis) or familial CRC for ha
rbouring mutations within the relevant APC gene regions: exons 1-5, exon 9
and a region within exon 15 (spanning nucleotides c.3900 to c.4034; codons
1294 to 1338) using denaturing gradient gel electrophoresis (DGGE), and all
of exon 15 employing protein truncation test (PTT). No inactivating, disea
se-associated mutations were detected in any patient. A novel polymorphism
in intron 5 was detected in 16 individuals, 8 patients were carriers of the
11307K variant, a mutation prevalent among Jewish individuals with colorec
tal cancer, and 4 displayed the E1317Q variant. We conclude that in Israeli
individuals with early onset or familial CRC, truncating mutations in the
APC gene regions associated with attenuated APC phenotype probably contribu
te little to disease pathogenesis. (C) 2001 Cancer Research Campaign.