New mutations in the APC gene in familial adenomatous polyposis: detection, characterization, and analysis.

The spectrum of mutations in the APC gene in familial adenomatous polyposis was detected in a sampling from the Russian population. Fifteen new mutations were found. Deletions associated with the loss of only 1 or 2 nucleotides (89% cases) prevailed among new (unique) mutations, while all known deletions were caused by the loss of 4 or 5 nucleotides. The detected differences in the deletion characteristics between unique and repeated mutations in the APC gene were typical of samples of patients from a number of populations. Samplings from different populations were heterogeneous by this sign. The incidence of 1-2-nucleotide deletions among unique and repeated deletions in the APC gene in patient samplings from different countries were in negative correlation.