Haploinsufficiency of A20. Failed colchicine and azathioprine monotherapies. Initial fill improvement of adalimumab then azathioprine and infliximab combination, developed antibodies to anti-TNFα. Severe flare with fever, oral ulcers, perianal ulcers livedo reticularis and colitis requiring 8 weeks of tapering prednisolone and now stable and symptom free on ustekinumab off steroids. Mother, but not other mildly affected relatives, also found to have TNFAIP3: p.C657Vfs*14 mutation. This case is being further investigated for additional genetic cause of his aqueduct dilation. The gene discussed is TNFAIP3; the disease is Oral ulcer.