Frequent polymorphism in exon 15 of the adenomatous polyposis coli gene.

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