Odor-prints: individual but genetic connections unclear

Odor is like fingerprints or facial features - it's unique.  Yet no single measurement could be easily applied to recognize an individual.

GC/MS measurements can be used to analyze mixtures of acids, alcohols, aldehydes, hydrocarbons, esters, ketones, and nitrogenous molecules in human odor. Complex algorithms mining patterns help to pinpoint the signatures. But could these signatures be easily derived from genetic makeups?

Recent article published in the Journal of Chemical Ecology looked at the usual suspects -  major histocompatibility locus (MHC) and found that these genes do not determine major patterns. 


Volatile carboxylic acids are the most diverse class of known axillary odorants, and the pattern of these acids is genetically determined. These acids  - like vast majority of human odorous compounds - are produced by human microbiome, in this case by skin bacteria. Odors of 12 families, comprising 3 to 6 siblings,were analyzed with comprehensive two-dimensional gas chromatography (GC x GC) and time-of-flight mass spectrometry (ToF MS). the analysis onfirmed the presence of individual signatures. but failed to find odors specific to HLA genes.

Even though paternally inherited HLA-associated odors were proposed to influence women odor preferences, genetic basis of odors may be more complicated than previously thought.

References

Natsch A, Kuhn F, & Tiercy JM (2010). Lack of Evidence for HLA-Linked Patterns of Odorous Carboxylic Acids Released from Glutamine Conjugates Secreted in the Human Axilla. Journal of chemical ecology PMID: 20623248

Thompson EE, Haller G, Pinto JM, Sun Y, Zelano B, Jacob S, McClintock MK, Nicolae DL, Ober C. (2010) Sequence variations at the human leukocyte antigen-linked olfactory receptor cluster do not influence female preferences for male odors. Hum Immunol. 2010 Jan;71(1):100-3. PMID: 19833159 
 
Jacob S, McClintock MK, Zelano B, Ober C (2002) Paternally inherited HLA alleles are associated with women's choice of male odor. Nature Genet 30: 175-179  PMID: 11799397  PDF