The Gardner syndrome: a family study in cell culture.

The occurrence of tetraploidy was studied in skin cultures containing both epitheloid and fibroblastic cells derived from 137 members (28 clinically affected, 50 normals at risk and 59 normals not at risk) of 6 families with the Gardner syndrome (3 classical, 3 variant). The cultures from all 28 affected members showed increased tetraploidy. Among the 50 normal members at risk for inheriting the Gardner gene, the cultures from 19 had increased tetraploidy and those from 31 did not. Cultures from 56 of the 59 family members not at risk did not show increased tetraploidy. Although the families were divided into subgroups (classical and variant) on clinical phenotypes, no such subdivision could be made on the basis of increased tetraploidy in skin cultures.