ADA2 and polyarteritis nodosa: Occasionally, a recessive loss-of-function mutation in the CECR1 gene, encoding deaminase A, has been associated with cPAN in children, pointing to a genetic susceptibility.[9,10] Whereas PAN patients may present with findings indicating visceral involvement,[1] in cPAN, the lesions are limited to the skin, adjacent muscles, nerves, and joints.