Detection of 12 germ-line mutations in the adenomatous polyposis coli gene by polymerase chain reaction.

Abstract

The adenomatous polyposis coli (APC) gene at chromosome 5q21 that is responsible for familial adenomatous polyposis (FAP) was recently isolated, and germ-line mutations in a substantial number of FAP families were characterized. Based on this information, the authors attempted to develop a presymptomatic diagnosis test for members of families that carry FAP. A rapid screening procedure using a polymerase chain reaction (PCR) method without radioisotopes, if necessary, coupled with digestion of restriction enzymes has been performed by detection of germ-line mutations that alter the size of DNA fragments or affect the recognition site of restriction enzymes in the APC locus. A rapid screening procedure to detect germ-line mutations at 12 loci that cause adenomatous polyposis was established. Using these 12 systems, presymptomatic diagnoses can be made with 100% accuracy within 24 hours. The procedures will be useful for counselling of members in some FAP families, which accounted for nearly 40% of the 95 FAP kindreds that have been detected by the germ-line mutations so far.