The Gardner syndrome: increased tetraploidy in cultured skin fibroblast.

Tetraploidy was increased in skin fibroblast cultures grown in the laboratory at the same time under the same conditions and derived from 2 probands with the Gardner syndrome and 9 affected members of one family as compared to that occurring in cultures from 5 relatives by marriage and 10 normals. Tetraploidy was present at the first subculture (2 weeks after the initial biopsy was cultured), and for each line studied the percentage of dividing cells showing tetraploidy remained constant. The relation of the observed tetraploidy to the increased risk of such patients to develop abnormal growths and cancer has not been established. The increased tetraploidy should be of value in identifying the presence of the gene for the Gardner syndrome in high risk families.