Susceptibility to infection in early life: a growing role for human genetics

Hum Genet. 2020 Jun;139(6-7):733-743. doi: 10.1007/s00439-019-02109-2. Epub 2020 Jan 13.

Abstract

The unique vulnerability to infection of newborns and young infants is generally explained by a constellation of differences between early-life immune responses and immune responses at later ages, often referred to as neonatal immune immaturity. This developmental view, corroborated by robust evidence, offers a plausible, population-level description of the pathogenesis of life-threatening infectious diseases during the early-life period, but provides little explanation on the wide inter-individual differences in susceptibility and resistance to specific infections during the first months of life. In this context, the role of individual human genetic variation is increasingly recognized. A life-threatening infection caused by an opportunistic pathogen in an otherwise healthy infant likely represents the first manifestation of an inborn error of immunity. Single-gene disorders may also underlie common infections in full-term infants with no comorbidities or in preterm infants. In addition, there is increasing evidence of a possible role for common genetic variation in the pathogenesis of infection in preterm infants. Over the past years, a unified theory of infectious diseases emerged, supporting a hypothetical, age-dependent general model of genetic architecture of human infectious diseases. We discuss here how the proposed genetic model can be reconciled with the widely accepted developmental view of early-life infections in humans.

Publication types

  • Review

MeSH terms

  • Gene Expression Regulation, Developmental*
  • Genes / genetics*
  • Genetic Diseases, Inborn / complications*
  • Genetic Diseases, Inborn / genetics
  • Genetic Predisposition to Disease*
  • Genetic Variation*
  • Human Genetics
  • Humans
  • Infections / etiology*
  • Infections / pathology