In human genetics, individuals are categorized based on their ability to secrete certain blood group antigens into bodily fluids such as saliva, tears, and mucus. This classification distinguishes between those who express these antigens in their secretions and those who do not. For instance, a person whose blood type is A and is also a secretor will have A antigens present not only on their red blood cells but also dissolved within their saliva. Conversely, a non-secretor with type A blood will only have A antigens on their red blood cells, with none detectable in their saliva.
The secretor status, determined by the FUT2 gene, has implications beyond simple blood typing. It is associated with varying susceptibility to certain infections, including norovirus and some bacterial infections. Historically, understanding this genetic trait has been crucial in fields like anthropology and forensic science. The presence or absence of these antigens in bodily fluids provides valuable information about an individual’s genetic makeup and potential predispositions.
