Clinical features of a human Rac2 mutation: a complex neutrophil dysfunction disease.

The case of an infant with multiple, rapidly progressive, soft-tissue infections is presented. Despite features suggesting a neutrophil disorder, results of screening tests of phagocyte function were normal. A novel, multifaceted leukocyte disorder-distinguished by defects in shape change, chemotaxis, ingestion, degranulation, superoxide anion production, and bactericidal activity-was established secondary to a defect in Rac2.