Abstract
Granulomatous inflammatory diseases are disorders of an undetermined etiology, affecting different organs and having a diverse clinical course. Familial aggregation of these disorders is being reported increasingly, most commonly familial Crohn's disease. We described the coexistence of Crohn's disease and necrotizing sarcoid-like granulomatous disease in two siblings from a first-degree consanguineous Saudi family. The first child presented with recurrent abdominal pain associated with bloody stool and arthritis, whereas the second child presented with fever of unknown origin and lymphadenopathy as well as hepatomegaly without gastrointestinal tract disease. They are phenotypically different; however, they share a novel risk locus and allele. This report supports the heritability and familial aggregation of granulomatous inflammatory diseases and suggests that one causal mutation underlies both Crohn's disease and necrotizing sarcoid-like granulomatous disease.