<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by arrhythmogenic right ventricular cardiomyopathy ? [/INST] ARVC occurs in an estimated 1 in 1,000 to 1 in 1,250 people. This disorder may be underdiagnosed because it can be difficult to detect in people with mild or no symptoms. </s>