In a recent genome-wide meta-analysis, researchers identified six sequence variants that confer risk of vertigo.
The inner ear and vertigo
The inner ear is a complex system that plays an important role in hearing and balance. Our balance, more specifically, is controlled by the vestibular system, which includes the parts of the inner ear and brain that process sensory information. Disruption to the normal function of this system, both peripherally and centrally, can result in vertigo.
Vertigo is the disturbing illusion of motion of oneself or the environment. It is the leading symptom of various diseases and conditions, such as migraine, adverse drug effects and disturbed blood pressure regulation. It is also a major risk factor for falls and bone fractures. As a result, it places a huge burden on the healthcare system.
Previous genome-wide association studies (GWAS) have yet to explore the broad phenotype of vertigo. In addition, current diagnoses of specific vestibular disorders rely on clinical criteria as there are no diagnostic biomarkers available.
Genome-wide meta-analysis on vertigo
In a recent study, published in Communications Biology, researchers performed a GWAS meta-analysis on vertigo in individuals of European ancestry. The team specifically combined data from Iceland, the UK, the US and Finland to uncover any associated risk loci.
Their analysis uncovered six associations at six different loci in genes with known roles in inner ear development, maintenance, and disease. These included: missense variants in ZNF91, OTOG, OTOGL, and TECTA, and a cis-eQTL for ARMC9. The association of variants in ZNF91, OTOGL, and OTOP1 were specifically driven by an association with benign paroxysmal positional vertigo.
Then, using previous reports of sequence variants that are associated with age-related hearing impairment and motion sickness, the team found an additional eight variants that were associated with vertigo. While vertigo and hearing loss can co-occur in some inner ear disorders, such as Menière’s disease, the six variants identified from the GWAS were not associated with hearing loss. Only one of these variants was associated with a low risk of age-related hearing impairment.
Overall, this study has uncovered variants associated with vertigo and implicated genes with key roles in the functioning of the inner ear. These findings further contribute to our understanding of the biological underpinnings of the vestibular and auditory systems. Nonetheless, further functional studies are required to help disentangle the role of vertigo-associated variants.
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