Deficiency of interleukin-1 receptor-associated kinase 4 presenting as fatal Pseudomonas aeruginosa bacteremia in two siblings.

Interleukin-1 receptor-associated kinase 4 (IRAK-4) deficiency is a primary immunodeficiency of innate immunity. This is the case of a previous healthy toddler and his sibling, who both died of fulminant sepsis due to Pseudomonas aeruginosa. Subsequent genetic analysis demonstrated IRAK-4 deficiency with compound heterozygous splice mutations. Fulminant fatal P. aeruginosa sepsis may be the first manifestation of IRAK-4 deficiency.