Natural history and outcomes. Ai and Aii : Serial 64-slice CT scans done in Proband 4 after an interval of 11 months showing progressive enlargement and tortuosity of descending aorta.Bi and Bii : Graphs showing the increase in the absolute dimensions and the respective Z-scores, of Ascending Aorta,Aortic Root and Main Pulmonary Artery in serial 64-slice CT scans in Proband 4 (at interval of 11 months) and Proband 5 (at interval of 6 months). C: Kaplan Meier Survival Graph for the homozygous mutant patients. D : Scatter diagram for the entire cohort, showing the ages at death. Currently surviving probands are encircled.