Are infectious diseases caused by human genes?

Infectious diseases are caused by microorganisms such as bacteria and viruses, not primarily determined by human genes. However, certain genetic predispositions can affect an individual's susceptibility to particular infections or influence the severity of the illness. Genes can play a role in immune response, immune deficiencies, and the expression of specific receptors that facilitate the entry of pathogens into the body. Nonetheless, infectious diseases are primarily caused by external factors, like exposure to pathogens or their transmission through various means, rather than solely determined by human genetics.