Abstract
A medical genetic reinvestigation of Family “G,” originally undertaken by Warthin in 1895, revealed that there are now more than 650 blood relatives, 95 of whom developed malignant neoplasms, 13 with multiple primary malignant neoplasms (14%). Considering age 40 and older as a cancer risk age correction, it was found that 35% of the members of the cancer susceptible branches of the family developed cancer. The incidence of cancer varied greatly among the several branches of the family (from 0 to 62%). Adenocarcinomas of colon, endometrium, and stomach predominated. However, in contrast to the cancer family syndrome, increased incidences of leukemia and sarcoma were found. Forty‐one sibships in 8 branches of the family showed cancer in 2 or more generations (5 generations in 3 sibships). The sex ratio of males to females affected approached 1 to 1. Findings in this kindred were consistent with autosomal dominant inheritance, though this cancer‐susceptible genome may be interacting with exogenous factors (oncogenic virus?).