Association of Single-Nucleotide Polymorphisms in Sweet Taste Perception and Intake Genes with Primary Ciliary Dyskinesia and Its Clinical Phenotypes

Primary ciliary dyskinesia (PCD) is a congenital motile ciliopathy causing impaired mucociliary clearance and characterized by recurrent respiratory infections affecting both the upper and lower airways. Several genes involved in taste perception pathways are expressed in extraoral tissues and have recently emerged as regulators of airway immune responses. This study aimed to (1) analyze potential correlations between PCD clinical manifestations and (2) investigate whether genetic variants within sweet signaling genes (SweetG) could be associated with PCD features. A total of 17 SNPs in nine SweetG were tested for differences in allele frequency between patients and the gnomAD European reference population using a binomial test. Regression models were used to evaluate associations between SweetG-SNPs and clinical features of patients. A cohort of 34 patients (10-69 years, 44.1% male) was included in the study. Regarding (1), a moderate/high correlation was identified among the clinical manifestations of the pathologies. Regarding (2), the minor alleles of rs5415 (<i>SLC2A4</i> gene) and rs838133 (<i>FGF21</i> gene) were less frequent in patients than in the reference population (<i>p</i> < 0.05). In addition, rs5415 and rs838133 were associated with the presence of chronic rhinosinusitis and <i>situs inversus</i>, respectively (<i>p</i> < 0.05). This study reveals associations between SweetG-SNPs and PCD as well as its specific clinical features, suggesting a potential link between sweet signaling pathways and PCD clinical variability. Although larger multicenter studies are warranted to validate these findings, they represent a promising area of research that can enhance our understanding of PCD and elucidate the genetic basis of clinical manifestations associated with the disease.