An international research team led by scientists at Leipzig University has conducted a genome-wide association meta-analysis of olfactory identification in over 21,000 individuals of European descent, identifying ten genetic regions associated with the ability to detect specific odours, seven of which are newly discovered. Participants in the Leipzig LIFE Adult Study and partner studies identified twelve everyday scents using scent pens, with responses compared to genetic data; notably, three of the identified regions exhibited sex-specific effects, and a link was observed between odour detection ability and risk of Alzheimer’s disease, suggesting interconnection with sex hormones and neurodegenerative diseases. The study, published in Nature Communications, revealed that genetic effects were specific to individual odours, with no single locus influencing perception of multiple smells.
The recent genome-wide association meta-analysis of human olfactory identification, conducted by researchers at Leipzig University and detailed in Nature Communications, revealed notable differences in how genes influence the sense of smell between men and women. The study, encompassing data from over 21,000 individuals of European descent, identified three genetic regions exhibiting sex-specific effects – meaning their function relating to odour perception differs between the sexes. This finding expands upon the ten genetic regions overall associated with the ability to detect specific odours, seven of which represent new discoveries in the field of human olfactory genetics.
These sex-specific genetic influences may contribute to observed differences in olfactory perception, such as variations experienced by women during their menstrual cycle or pregnancy. The researchers posit that these findings could facilitate more tailored medical diagnoses, acknowledging biological sex as a contributing factor. The analysis demonstrated that genetic effects were specific to individual odours assessed – including orange, shoe leather, cinnamon, and fish – and no single genetic locus universally influenced the perception of multiple smells. Further investigation into these sex-specific genetic variations is currently underway through the German National Cohort (NAKO Gesundheitsstudie), involving approximately 200,000 participants, with the aim of achieving a more detailed understanding of these complex interactions.
The identification of genetic regions associated with olfactory perception carries significant implications for understanding neurological disorders. The study established a link between the ability to detect odours and the risk of Alzheimer’s disease, reinforcing existing evidence of interconnectedness between the sense of smell, sex hormones, and neurodegenerative processes. This connection suggests that olfactory function may serve as an early indicator of, or contribute to the progression of, such diseases, warranting further investigation into the underlying mechanisms.
Currently, researchers are expanding upon this initial analysis through the German National Cohort (NAKO Gesundheitsstudie), a large-scale study involving approximately 200,000 participants. This expanded cohort will enable a more detailed examination of genetic and sex-specific differences in olfactory perception, potentially revealing novel biomarkers for early disease detection. The study’s findings, detailing ten identified genetic regions – seven newly discovered – associated with odour detection, provide a foundation for future research focused on the genetic basis of olfactory dysfunction and its relationship to neurodegenerative conditions. The granular level of analysis, identifying genetic effects specific to individual odours assessed – including orange, cinnamon, and fish – allows for a targeted approach to understanding how specific olfactory deficits might correlate with disease progression. Further research will focus on elucidating the precise biological pathways linking these genetic variants to olfactory function and neurological health, potentially paving the way for innovative diagnostic tools and therapeutic interventions.