A novel single variant in the MEFV gene causing Mediterranean fever and Behçet's disease: a case report.

Background: Familial Mediterranean fever is an autoinflammatory disease of unknown etiology, characterized clinically by recurrent attacks of sudden-onset fever with arthralgia and/or thoracoabdominal pain and pathogenetically by autosomal recessive inheritance due to a mutation in the MEFV gene. Behçet's disease is an inflammatory disease characterized by recurrent oral and genital aphthous ulcerations, uveitis, and skin lesions. Preliminarily, our literature review suggested that patients with familial Mediterranean fever who also have Behçet's disease have only a single mutated familial Mediterranean fever gene. The MEFV gene mutation responsible for familial Mediterranean fever is probably a susceptibility factor for Behçet's disease, particularly for patients with vascular involvement, and both disorders can occur concurrently in a patient, as in the present case.

Case Presentation: A 10-year-old girl of Moroccan origin presented to our institution for genetic consultation for genetic testing of the MEFV gene. She had fever associated with abdominal and diffuse joint pain in addition to headache. These symptoms have oriented pediatricians to familial Mediterranean fever. The evolution was marked by Behçet's syndrome symptoms. Sanger sequencing followed by complete exome sequencing analysis of the MEFV gene for the proband mutation revealed a novel variant. We conclude that the novel single variant c.2078 T > A (p.Met693Lys) could be responsible for the association of familial Mediterranean fever and Behçet's disease.

Conclusion: To the best of our knowledge, this is the first report of a new variant in exon 10 of the MEFV gene in a Moroccan family. This novel variant should be listed in the MEFV sequence variant databases.