Fig. 1. Aorta diameters in MPS VII dogs.

Echocardiograms were performed for normal dogs, untreated MPS VII dogs, and MPS VII dogs that received IV injection of 0.3 to 1×10¹⁰ TU/kg of the RV designated hAAT-cGUSB-WPRE at 2 to 3 days after birth (RV-treated). The latter achieved stable expression of GUSB activity in serum for the duration of evaluation. A. Representative images of aortas. Images are shown for one normal dog at 6 months (aortic dilatation score 0), one of 5 untreated MPS VII dog at 6 months (score +2), one of 13 RV-treated MPS VII dog at 6 months (score 0; dog M2420 with 317 U/ml of serum GUSB activity), and one of three RV-treated MPS VII dog that was evaluated at 8 years (score +2; M1332 with 111 U/ml of serum GUSB activity). The double-headed arrows indicate the inner diameters of the aorta at the position where dilatation was evaluated during diastole (top) and systole (bottom), and the left ventricle (LV) is indicated. For some images, the vertical single-headed arrows identify the narrowing of the aorta seen at the sinotubular junction in diastole, which is a normal finding. For other images, the horizontal single-headed arrow identifies a thickened base of the aortic valve that shows little movement during systole. The size marker represents 1 cm. B. Average aortic dilatation scores. Aortas were scored from 0 (normal) to +4 (severe dilatation) for the indicated (N) number of untreated MPS VII and RV-treated MPS VII dogs as shown in panel A, and the average +/− standard error of the mean (SEM) plotted. Normal dogs are not shown but generally have scores of 0. Untreated MPS VII dogs do not survive beyond 2 years. The Student’s t-test was used to compare values in the 2 groups at each time point where MPS VII dogs were evaluated, and * indicates a p value of 0.01 to 0.05, and ** indicates a p value <0.01.