Epidemiology The incidence rate of Aa: 74 per1003000, AAA:0.14per1003000 GAA:0.60per100,000 Distribution: most AA patients are young and middle-aged people, male more than femaleEpidemiology The incidence rate of AA :0.74 per 100,000， AAA : 0.14 per 100,000, CAA : 0.60 per 100,000. Distribution：most AA patients are young and middle-aged people, male more than female