Do you smell what I smell? Perhaps not, and it might not be due to a cold…Genetic variation in a human odorant receptor alters odour perception (Nature):
Human olfactory perception differs enormously between individuals, with large reported perceptual variations in the intensity and pleasantness of a given odour…A common variant of this receptor (OR7D4 WM) contains two non-synonymous single nucleotide polymorphisms (SNPs), resulting in two amino acid substitutions (R88W, T133M; hence ‘RT’) that severely impair function in vitro. Human subjects with RT/WM or WM/WM genotypes as a group were less sensitive to androstenone and androstadienone and found both odours less unpleasant than the RT/RT group. Genotypic variation in OR7D4 accounts for a significant proportion of the valence (pleasantness or unpleasantness) and intensity variance in perception of these steroidal odours. Our results demonstrate the first link between the function of a human odorant receptor in vitro and odour perception.
I’ve posted on sensitivity to taste and variation many times: PTC taste, balancing selection?, PTC, part II, Taste & behavior genetics, Genetics of taste and Slow & diverse food. We know that taste & smell tend to operate syngergistically, so variation along both sensory dimensions no doubt would increase the range of human variation on this phenotype due to the increase in the number of combinations. It might make us reflect on the role that critics of food & wine play in terms of how they serve as filters to other people when perception itself might differ so much from person to person.
Here’s a some data on the polymorphism from the HapMap.