Gardner's syndrome: six generations.

A family of 68 members in six generations has been investigated, and thus far 23 of these have had colorectal polyposis, cancer, or both. Many of the 23 have had a variety of soft tissue lesions, occult osteomas of the mandible, and dental abnormalities. Six of nine siblings in the proband's immediate family had diffuse colorectal polyposis and soft tissue lesions, as have 4 of their 20 children. One of three members of the most recent generation has polyposis and skin lesions. Retrospectively, 2 of the proband's 18 maternal cousins had colorectal polyposis or cancer, as did five of six siblings in her mother's generation. Four of nine siblings in the previous generation died from colon cancer, and so did their father. In the first three generations cancer was prevented in only 1 of 10 patients. Two of 13 in the later three generations thus far have died from colorectal cancer. Both coloproctectomy and colectomy with preservation of the rectum have been utilized in the patients in this study. Lifelong follow up is underway for those whose rectum has been removed.