Tuberculosis in twins: a re-analysis of the Prophit survey.

Data on tuberculosis in twins collected by Dr. Barbara Simonds for the Prophit Committee of the Royal College of Physicians of London were re-analyzed using multiple regression to control for the effects of variables other than zygosity. Concordance for tuberculosis was significantly higher among monozygotic than dizygotic twin pairs. This finding indicates that inherited susceptibility is an important risk factor for tuberculosis among humans.