The aim of the laboratory of human genetics of infectious diseases is to determine the genetic basis of predisposition or resistance to infectious diseases in humans. Two general working hypotheses guide the experimental approach used. Firstly, the microbial infectious agent is necessary, but not sufficient, for the development of an infectious disease. Secondly, there is a difference in the degree, rather than the nature, of the immunological and genetic defences of subjects developing rare opportunistic infections and those developing common infectious diseases. These two hypotheses give rise to the following assumptions :
- All humans have a hereditary immune deficiency if they are susceptible to at least one infectious agent.
- There is a genetic continuum and genetic variability determines resistance in humans, mirroring the genetic continuum and variability determining virulence in micro-organisms.