Clinical and genetic analysis of 24 Russian patients with attenuated form of family colon adenomatosis was undertaken. On the basis of obtained clinical and genetic data it was defined the algorithm of therapeutic measures in this group of patients--from dynamic monitoring or endoscopic polypectomy to performing extensive resections of the colon in situations associated with cancer development, an increase of the intensity of growth of polyps or an appearance of villous lesions. Some of the patients had molecular-genetics causes of a weakened form of family adenomatosis.