Autoinflammatory gene mutations in Behçet's disease.

BACKGROUND: Behçet's disease (BD) shares clinical features with well-recognised autoinflammatory disorders. In addition, mutations in genes for familial Mediterranean fever and tumour necrosis factor receptor-associated periodic syndrome have been reported to have increased in patients with BD. PATIENTS AND METHODS: DNA samples from 97 patients with BD and 51 matched healthy controls were analysed for the mevalonate kinase (MVK), cold-induced autoinflammatory syndrome 1 (CIAS1) and proline/serine/threonine phosphatase-interacting protein 1 (PSTPIP1) genes, responsible for mevalonate kinase deficiency (MKD), cryopyrin associated periodic syndromes (CAPS) and pyogenic sterile arthritis, pyoderma gangrenosum and acne (PAPA) syndrome, respectively. Over 90% of known mutations were screened using restriction fragment length polymorphism analysis and/or sequencing.
RESULTS: Two patients had paired mutations in the MVK gene (genotypes V377I/V377I and V377I/S135L) and displayed typical features of BD and MKD. Another was heterozygotic for the V377I genotype. The V198M mutation in the CIAS1 gene was identified in one patient with typical BD but no symptoms of CAPS. No mutations were identified in the control group. PSTPIP1 analysis revealed a new exon 10 insertion variant (c.741+33_741+34insGT) in 2 of 97 patients and in 1 of 51 controls (p>0.05), indicating that it is a polymorphism rather than a true mutation. DISCUSSION: This study could not demonstrate any significant increases in MVK, CIAS1 or PSTPIP1 mutations in patients with BD as compared with controls.