Aortic comparison of monozygotic twins and their nontwin siblings

Twin registries provide data on concordance of aneurysmal disease between twin sets, but provide no granular data. Four sets of monozygotic (MZ) twin families with aortic pathology and aortic imaging were identified within a single health care system to create a Dice score for aortic comparison. MZ twin Dice scores in families A through D were 32.3%, 34%, 46.5%, and 42.4% respectively. Nontwin siblings Dice scores were 31% and 33.2% for families B and C, respectively. Our case series illustrates that MZ twin aortas have higher rates of concordance compared with their nontwin siblings.