FREQUENT POLYMORPHISM IN EXON-15 OF THE ADENOMATOUS POLYPOSIS-COLI GENE

In the course of a study of tumor suppressor gene mutation in hepatobl astoma, a frequent neutral polymorphism was identified at codon 1493 i n exon 15 of the gene causing adenomatous polyposis coli (APC). As the polymorphism introduces a new BsaJ1 site, DNA amplified by the polyme rase chain reaction (PCR) can be rapidly screened for this polymorphis m. This polymorphism can be used in cosegregation studies for presympt omatic diagnosis of APC and family studies.