Splicing defects in the CFTR gene: minigene analysis of two mutations, 1811+1G>C and 1898+3A>G

Abstract

Background: Cystic fibrosis is caused by mutations of the Cystic Fibrosis Transmembrane conductance Regulator gene (CFTR). Among the 1795 reported mutations, 221 (12.31%) are believed to affect pre-mRNA splicing. Nevertheless, not all splicing mutations have been demonstrated, by functional assays, to affect splicing in living cells.

Methods: We have used a minigene-based approach, coupled to site-specific mutagenesis, to analyze the effects of presumptive pre-mRNA splicing mutations.

Results: We show here that the intron 11 1811+1G>C and the intron 12 1898+3A>G mutations strongly affected CFTR pre-mRNA splicing. The encoded proteins are predicted to be defective, which would thus participate in the disease phenotype of carrier individuals.

Conclusions: These results further validate the minigene strategy for the study of presumptive splice mutations, and report unanticipated defects in splicing. Such assays should improve the analysis of genotype-phenotype correlations.