Novel insight into CFTR gene's single nucleotide variants classification via in-silico analysis of a conserved site

Mutations in the CFTR gene play a pivotal role in the onset/severity of cystic fibrosis (CF). While our understanding of CFTR mutation classes is fragmented, this study focused on missense single nucleotide variants (SNVs) in the ABC transporter-like conserved site of the CFTR protein, employing various bioinformatics tools to identify deleterious amino acid substitutions (A.A.S). To gain a comparative understanding of the deleterious A.A.S in CFTR mutation classes, the in silico prediction of classified A.A.S by MutPred2 was cross-referenced with predictions of unclassified A.A.S. The study revealed twenty-five deleterious A.A.S in the conserved site. Nine of these (S549R, S549N, G551S, G551D, L558S, A559T, R560T, R560S, and A561E) were already classified. The in silico predictions for the remaining sixteen A.A.S exhibited similarities to molecular variations predicted for classified CFTR mutations and identified nine A.A.S falling under class II and seven A.A.S falling under class III, while four of these A.A.S in this conserved site may have effects of class II and III mutations. However, this classification is relative, warranting a comprehensive analysis to elucidate the intricacies of these nsSNVs. The combined use of modulators in therapy holds promise for more effective CF management, recognizing that CFTR mutations may exert effects that extend beyond a single class of mutation.