Blau syndrome

Blau syndrome is an autosomal dominant genetic inflammatory disorder that affects the skin, the eyes and the joints. It is caused by a mutation in the NOD2 gene, which is also written CARD15, and it is classified as an inborn error of immunity. Symptoms usually begin before the age of four. The disease shows itself as early onset cutaneous sarcoidosis, granulomatous arthritis and uveitis, which is inflammation inside the eye. The source frames it as a single-gene inflammatory condition rather than an infection, with the skin, eye and joint features appearing together in childhood.