The clinical manifestation of cystic fbrosis (CF) is heterogeneous also in patients with the same cystic
fbrosis transmembrane regulator (CFTR) genotype and in afected sibling pairs. Other genes, inherited
independently of CFTR, may modulate the clinical manifestation and complications of patients with
CF, including the severity of chronic sinonasal disease and the occurrence of chronic Pseudomonas
aeruginosa colonization. The T2R38 gene encodes a taste receptor and recently its functionality was
related to the occurrence of sinonasal diseases and upper respiratory infections. We assessed the T2R38
genotype in 210 patients with CF and in 95 controls, relating the genotype to the severity of sinonasal
disease and to the occurrence of P. aeruginosa pulmonary colonization. The frequency of the PAV allele
i.e., the allele associated with the high functionality of the T2R38 protein, was signifcantly lower in i) CF
patients with nasal polyposis requiring surgery, especially in patients who developed the complication
before 14 years of age; and ii) in CF patients with chronic pulmonary colonization by P. aeruginosa,
especially in patients who were colonized before 14 years of age, than in control subjects. These data
suggest a role for T2R38 as a novel modifer gene of sinonasal disease severity and of pulmonary P.
aeruginosa colonization in patients with CF
