Phenocopies of inborn errors of immunity

Abstract A phenocopy is defined as a clinical phenotype in an individual, noninherited, with environmental induction that is identical to the genetically determined phenotype of another. In parallel to immunity errors due to germline mutations of immune-related genes, a separate group of immune system disorders are defined with conditions that are not part of the these germline alterations called phenocopies. These tend to have a later onset and variable course. The first contact physician must know this type of pathologies that can occur at any stage of the patient’s life so that they are included within the differential diagnosis of diseases.