The Danish Polyposis Register. Description of the methods of detection and evaluation of completeness.

A manual Danish register of patients with familial polyposis coli and their family members was established in 1971. The methods of collection of propositi, preparation of pedigrees, collection of call-up cases, and the organization of the register are described. A country-wide prophylactic proctosigmoidoscopic examination of first-degree relatives, aged 10 to 59 years, resulted in the detection of 42 call-up cases and by December 1982, 319 cases of polyposis were registered in 94 families. An evaluation of the number of collected propositi and call-up cases shows almost complete registration.