The impact of genetic immune disorders on infections including COVID-19, inflammatory bowel disease and cancer.

Inborn errors of immunity (IEIs) are rare genetic anomalies that cause defective immune function. Over 500 IEIs have been identified to date, affecting millions of patients globally. These IEIs reveal the complex interplay between genetics, the environment and microorganisms that determine immune disease phenotypes. Progress in understanding the molecular and cellular mechanisms of IEIs provides a genetic framework for a functional understanding of the human immune system, disease pathogenesis and successful therapeutic interventions. This Review describes how IEIs impact infectious diseases, particularly coronavirus disease 2019, inflammatory bowel disease and cancer.