Diabetes Mellitus in Twins

Abstract

Among 242 sets of twins collected from 34,072 Joslin Clinic records from 1949 to 1966, there were 104 sets with both members alive. Of these, forty-seven sets were examined and an additional forty-three sets responded to a detailed questionnaire. A high concordance for overt diabetes was found in monozygotic sets in which the proband was age forty or greater at time of diagnosis. In the forty-seven sets examined, there were no cases of overt diabetes in the dizygotic twin siblings of a proband who was age forty and over at time of diagnosis of overt diabetes. Surprisingly, however, a high rate of chemical diabetes was diagnosed in the dizygotic twin siblings, an observation implying an etiology for diabetes mellitus more complex than inheritance by a single recessive gene.