Nasal polyposis and cystic fibrosis (CF): review of the literature

The aim of this study was to address whether NP might be a predictive factor for severity of CF. The authors collected data from the literature on NP as a unique or associated sign in CF and reviewed the clinical and molecular aspects of CF associated with NP. CF genotypes and clinical severity in NP(+) vs. NP(-) patients were reviewed, taking into account pulmonary function, frequency of P. aeruginosa lung infection, frequency of allergy, nutritional status, and exocrine pancreatic Junction. The CFTR gene was also analyzed in a patient with isolated severe NP as the unique feature of CF. This review of the literature showed a 'milder' phenotype in 'NP+' vs. 'NP-' CF patients, contrasting with a marked association between NP and 'severe' CF mutations. In addition, a complex genotype was identified, associating four heterozygous variants, namely p.Q493X (a severe mutation) on the paternal allele, and p. V5621, p.A1006E, and (TG)11(T)5 (IVS8-5T) on the maternal allele, in a case of CF presenting as isolated NP. The authors speculate that geneticlenvironmental factors associated with NP might attenuate the functional impact of 'severe' CF mutations. The overrepresentation of CF carriers among patients with isolated NP also advocates the need for CFTR molecular screening in,such populations for genetic counselling purposes.