Patient 2 harbors a 2.18 Mb heterozygous deletion on chromosome 6 (6q23.3), resulting in the loss of 13 protein-coding genes, notably TNFAIP3, PEX7, IL20RA, and IL22RA2. The TNFAIP3 deletion, causative of HA20, underlies the core Behçet’s-like phenotype characterized by fever, abdominal pain, diarrhea, hematochezia, skin eruption, Oral aphthosis and genital aphthosis, intestinal ulcers, and arthritis. This evidence concerns the gene TNFAIP3 and arthritic joint disease.