Characterization of the genetic basis of human olfactory variance

PIs:

Hanns Hatt (Bochum)

Günter Gisselmann (Bochum)

Thomas Hummel (Dresden)

The ability to detect individual odors is highly variable between individuals. For many chemicals, a high percentage of the human population is specifically anosmic. On an individual basis all humans are expected to have some of such specific anosmias. The reason underlying this individual variance is largely unknown. In the last years, research on human genomics intensively focused on genetic variations between individuals. One of the main reasons for individuality is the occurrence of millions of single nucleotide polymorphisms (SNPs) making each genome unique. Recently, it was shown that SNPs in odorant receptor genes may be one of the general principles for partial anosmias. In the proposed project, we plan to characterize the genetic basis of human variation in odor perception by analyzing SNP variations or copy number variations related to several well defined and frequent occurring anosmic phenotypes. The ultimate goal is to identify corresponding genes and the SNP patterns responsible for 'smeller' and 'non-smeller' alleles and use this information also for deorphanization of receptors. Our knowledge about the genetic variation within the human population is still fragmentary, and present SNP databases cover naturally occurring SNPs only partially. Therefore, we additionally intend to analyze genetic variations of several selected odor receptor genes to gain profound insights into differences within the main worldwide human populations. On a behavioral level, it is planned to investigate whether odor sensitivity can be acquired over a period of several months, even when subjects initially exhibit a specific anosmia towards this odor. The proposed project will elucidate the genetic basis of variations in human odor perception and moreover enhance or understanding about the mechanisms creating an individual 'unique smeller' in terms of odor sensitivity and rating.