Genetic determinants of swallowing impairments among community dwelling older population

Swallowing difficulties (dysphagia) affect a significant proportion of community dwelling older individuals, being more prevalent in age-associated neurological conditions such as stroke and Parkinson's disease. The genetic determinants of dysphagia are still being explored and have largely been studied through candidate gene analysis approaches. The aim of the study was to perform a genome-wide association study (GWAS) of common genetic single nucleotide polymorphisms (SNP) and self-reported swallowing impairments in a longitudinal cohort of community dwelling older adults.

We performed a case-control genome-wide association study of self-reported swallowing symptoms using the Sydney Swallow Questionnaire. The analysis included 555 community dwelling, unrelated, older adults (mean years of age=81.4; SD=5.349) with known phenotype and genetic information consisting of 512,806 single nucleotide polymorphisms. Gene-based association analysis of these traits was also conducted.

Analysis of the cohort confirmed European ancestry with no major population stratification. Further analysis for association with swallowing impairment identified one SNP rs17601696 which achieved genome-wide significance (P-value=5×10(-8)) within a non-coding region of chromosome 10. Gene-based analysis did not result in any genome-wide significant association.

SNP rs17601696 may have an impact on swallowing impairment among elderly individuals. The results require replication in an independent cohort with appropriate phenotype/genotype data.