Sequence Variants in TAAR5 and Other Loci Affect Human Odor Perception and Naming

Area of Science:

• Genetics
• Olfaction Science
• Human Physiology

Background:

• Human olfactory receptor (OR) genes exhibit high DNA sequence diversity, suggesting potential variations in odor perception and behavior.
• Understanding the genetic basis of olfaction is crucial for explaining individual differences in sensory experiences.

Purpose of the Study:

• To investigate the association between genetic variations and human odor perception and naming.
• To identify specific olfactory receptor (OR) genes and variants influencing the perception of common odors.

Main Methods:

• Conducted a large-scale genome-wide association study (GWAS) involving 9,122 Icelanders and replicated findings in 2,204 individuals.
• Utilized olfactory testing, including smell tasks, to assess odor perception and naming abilities.
• Analyzed genetic data to identify significant associations between gene variants and odor responses.

Main Results:

• A missense variant in TAAR5 (p.Ser95Pro) was associated with reduced intensity perception of fish odor (trimethylamine).
• TAAR5 genotype variations influenced aversion to fish odor, affecting linguistic descriptions and pleasantness ratings.
• Common variants in OR6C70 (p.Lys233Asn) and an intergenic variant (rs317787-T) were linked to enhanced intensity and naming of licorice (trans-anethole) and cinnamon (trans-cinnamaldehyde) odors, respectively.

Conclusions:

• Genotype variations in TAAR5 significantly influence human responses to fish odor.
• Sequence diversity in canonical olfactory receptor genes, such as OR6C70, can lead to enhanced olfactory abilities, challenging previous notions of diminished function due to mutation tolerance.