Hereditary Periodic Fever

Fever of undetermined origin may be familial and have a periodic course. This article discusses three syndromes of hereditary periodic fever: familial Mediterranean fever, the hyper-IgD syndrome, and the tumor necrosis factor receptor–associated periodic syndrome. Each is caused by mutations in different genes and affects different ethnic groups. Important recent advances in our understanding of the pathophysiology of these disorders are presented in this review article.