Heritability of Anosmia

Folks with anosmia sometimes wonder to what extent anosmia is genetically caused. One can argue that everything about our bodies is the result of an interaction between our genetic structures and our environment. That aside, there are a number of diseases that have been associated with particular genetic abnormalities and which may include anosmia as one of their common symptoms. Among the better know of these diseases is Kallmann syndrome and Refsum disease, but most persons who suffer anosmia have neither of these conditions. There are very many factors that can lead to anosmia, and many, maybe even most, of these have a considerable heritability. Even causes that are proximally associated with infectious agents, such as virally induced anosmia, may be heritable - that is, those with certain genetic structures may be much more likely to react to the virus in a way that causes anosmia. One could even argue that "accidental" anosmia has a heritable component, if one accepts that one's genetic background can make one more or less likely to have accidents. My own anosmia is associated with polyposis, inflammatory reactions of certain tissue in my body, allergy, infection, imbalance of the autonomic nervous system, irritants in my environment, and genetics. Other persons exposed to the agents which cause the inflammatory reaction do not react in a way that leads to anosmia, presumably because they have a different genetic structure than do I.