High-resolution karyotypes of eighteen Norwegian polyposis patients.

Abstract High-resolution karyotypes were analyzed from lymphocyte cultures of 18 Norwegian polyposis patients, of whom two had classic Gardner syndrome [GS]. We focused on possible rearrangements of the long arm of chromosome 5. Previously the gene for familial adenomatous polyposis (FAP) was localized to the region 5q21–22 by linkage analysis. A patient with a constitutional deletion in this region would be of great value in the course of cloning the gene. At the level of high-resolution G-banding, however, none of these patients showed any interstitial deletion or other rearrangement on chromosome 5 or any other chromosome.