NOD2 and polyarticular arthritis: Blau syndrome, which may represent the same disease as early-onset childhood sarcoidosis, is an autosomal-dominant monogenic granulomatous syndrome associated with mutation in the nucleotide binding oligomerization domain containing 2 (NOD2) gene that causes the classic triad of uveitis, rash, and polyarthritis with onset in the first few years of life [2].