In conclusion, the ID genotype is present in a significantly higher frequency and DD in lower frequency among Kawasaki disease patients than in control subjects. In addition, there are no significant association between ACE I/D polymorphism and the coronary artery aneurysm formation in Kawasaki disease patients. Because the study groups are relatively small size in number, it is difficult to generalize these results. In this study, the coronary arterial dilatation was observed in 17 out of 55 Kawasaki patients. This is higher than that in previously reported literature. It can be accounted for either 1) longer duration from the onset of illness to the infusion of immunoglobulin, 2) other factors that may affect the development of coronary arterial lesions in Kawasaki disease, such as different ethinicity or 3) selection bias caused by limited number of enrolled institution and small number of patients. IVIG is recommended to be given within the first 10 days of illness and, if possible, within 7 days of illness. Since the duration of febrile days before the diagnosis and the IVIG infusion were 4.6±1.6 days (range, 2-8 days) in our study groups, the first explanation seems less likely.