In One Study with Both Monozygotic and Dizygotic Twins, the Concordance

Multiple Choice

In one study with both monozygotic and dizygotic twins, the concordance value for a neurological disorder was 100% for monozygotic twins. Which of the following statements is CORRECT?

A) The concordance value for dizygotic twins will be also 100%.
B) There will be no phenotypic variation in susceptibility for the disorder for all the pairs of twins in the study.
C) The concordance value for dizygotic twins will be 25%.
D) For dizygotic twins, all the variation in susceptibility for the disorder will be due to environmental factors.
E) Most of the variation in susceptibility for the disorder for monozygotic twins is likely due to genetic factors assuming that the concordance value for dizygotic twins is significantly less than 100%.