Effect of the F508del genotype on outcomes of endoscopic sinus surgery in children with cystic fibrosis.

OBJECTIVE: Numerous authors have sought to describe genotype-phenotype correlations in cystic fibrosis (CF), notably to pancreatic insufficiency and lung disease. However, few studies have focused on the association between the F508del genotype and response to sinus surgery. The objective of this study is to assess the effect of the F508del genotype on sinonasal disease severity and outcomes following functional endoscopic sinus surgery (FESS) in a pediatric population.

METHODS: A retrospective chart review of 153 children with CF seen at a tertiary care pediatric hospital from 1995 to 2008 was performed. Patients were classified into one of three groups according to F508del genotype, either as homozygous, heterozygous or not carrying a F508del mutation. The sinonasal disease phenotype of the three groups was compared based on clinical and radiological findings, extent of endoscopic sinus surgery and rate of revision surgery.

RESULTS: The relationship between the F508del genotype and pancreatic insufficiency was confirmed (p<0.05). There was no association between the F508del genotype and increased need for FESS (p=0.75). Moreover, no association was established between F508del homozygosity and presence of nasal polyps, Lund-Mackay score, extent of surgery or length of postoperative hospitalization. The rates of revision surgery did not differ significantly among the three genotypes analyzed (p=0.59).

CONCLUSION: There is no clear association between the F508del genotype and an increased need for FESS, extent of surgery, or revision surgery. Given the phenotypic variability of sinonasal disease in patients with CF, a prospective study is needed to better understand outcomes following FESS and the contribution of gene modifiers to this effect.