Gene mutations and clinical phenotypes in Chinese children with Blau syndrome.

The mutations of CARD15 gene and clinical features of Chinese patients with Blau syndrome were analyzed. We identified 10 missense mutations, out of which five were new: R334L, E383D, R471C, C495R and D512F. The rest of them, R334W, R334Q, G481D, M513T and R587C, have been reported previously. Among all the mutations, R334W, R334Q and C495R had the highest frequency. Blau syndrome was found at early age after birth. It began with lepidic rash and symmetric polyarthritis and was phenotypically characterized by typical rash, arthritis, iridocyclitis and arteritis. Cardiac involvement was also found in Blau syndrome. In addition to nerve deafness, renal involvement, osteochondroma and central nervous system involvement were also found in our patients. Therefore, Chinese children with Blau syndrome have unique gene mutations and complicated clinical phenotypes. Pathologic examination and CARD15 mutation testing should be considered for diagnosis as early as possible for suspected patients.