SCENTinelTM - a rapid, inexpensive smell test that measures odor detection, intensity, identification, and pleasantness - was developed for population-wide screening of smell function. SCENTinelTM was previously found to screen for multiple types of smell disorders. However, the effect of genetic variability on SCENTinelTM test performance is unknown, which could affect the tests validity. This study assessed performance of SCENTinelTM in a large group of individuals with a normal sense of smell to determine the test-retest reliability and the heritability of SCENTinelTM test performance. One thousand participants (36 [IQR 26-52] years old, 72% female, 80% white) completed a SCENTinelTM test at the 2021 and 2022 Twins Days Festivals in Twinsburg, OH, and 118 of those completed a SCENTinelTM test on each of the festivals two days. Participants comprised 55% percent monozygotic twins, 13% dizygotic twins, 0.4% triplets, and 36% singletons. We found that 97% of participants passed the SCENTinelTM test. Test-retest reliability ranged from 0.57 to 0.71 for SCENTinelTM subtests. Broad-sense heritability, based on 246 monozygotic and 62 dizygotic twin dyads, was low for odor intensity (r=0.03) and moderate for odor pleasantness (r=0.4). Together, this study suggests that SCENTinelTM is a reliable smell test with only moderate heritability effects, which further supports its utility for population-wide screening for smell function.

On behalf of MEH VP PHD and DRR the Monell Chemical Senses Center and Temple University have been awarded patent protection (US patent no. 11 337 640) and this patent has been licensed to Ahersla Health Inc. The authors may benefit financially through their institutions patent policy. SRH CL KB AH and PVJ declare no conflicts of interest.

We acknowledge support from the National Institutes of Health as part of the RADx-rad initiative (U01 DC019578 to PHD and VP). SH was supported by NIH T32 funding (DC000014) and F32 (DC020658) during this work. MEH was supported by NIH T32 (DC000014) and F32 (DC020100) funding during this work. PVJ is supported by the Division of Intramural Research National Institute on Alcohol Abuse and Alcoholism (Z01AA000135) and National Institute of Nursing Research and the Office of Workforce Diversity, National Institutes of Health Distinguished Scholar, and the Rockefeller University Heilbrunn Nurse Scholar Award.

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