Autosomal recessive Interleukin-1 receptor-associated kinase 4 deficiency in fourth-degree relatives

We report a kindred with autosomal recessive interleukin-1 receptor-associated kinase 4 (IRAK-4) deficiency in 3 fourth-degree relatives. A diagnosis of IRAK-4 deficiency should be considered in families with invasive bacterial disease, even if the individuals affected are only distantly related, which falsely suggests multigenic or dominant inheritance with low penetrance.