title: Molecular and functional analysis of the large 5' promoter region of CFTR gene revealed pathogenic mutations in CF and CFTR-related disorders.
abstract: Patients with cystic fibrosis (CF) manifest a multisystemic disease due to mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR); despite extensive testing of coding regions, a proportion of CF alleles remains unidentified. We studied 118 patients with CF and CFTR-related disorders, most with one or both unknown mutations after the scanning of CFTR coding regions, and a non-CF control group (n = 75) by sequencing the 6000-bp region at the 5' of the CFTR gene. We identified 23 mutations, of which 9 were novel. We expressed such mutations in vitro using four cell systems to explore their functional effect, relating the data to the clinical expression of each patient. Some mutations reduced expression of the gene reporter firefly luciferase in various cell lines and may act as disease-causing mutations. Other mutations caused an increase in luciferase expression in some cell lines. One mutation had a different effect in different cells. For other mutations, the expression assay excluded a functional role. Gene variants in the large 5' region may cause altered regulation of CFTR gene expression, acting as disease-causing mutations or modifiers of its clinical phenotype. Studies of in vitro expression in different cell systems may help reveal the effect of such mutations.
authors.affiliation: CEINGE-Biotecnologie Avanzate S.c.ar.l., Naples, Italy.
authors.forename: Sonia
authors.initials: S
authors.lastname: Giordano
authors.forename: Felice
authors.initials: F
authors.lastname: Amato
authors.forename: Ausilia
authors.initials: A
authors.lastname: Elce
authors.forename: Maria
authors.initials: M
authors.lastname: Monti
authors.forename: Carla
authors.initials: C
authors.lastname: Iannone
authors.forename: Pietro
authors.initials: P
authors.lastname: Pucci
authors.forename: Manuela
authors.initials: M
authors.lastname: Seia
authors.forename: Adriano
authors.initials: A
authors.lastname: Angioni
authors.forename: Federica
authors.initials: F
authors.lastname: Zarrilli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Castaldo
authors.forename: Rossella
authors.initials: R
authors.lastname: Tomaiuolo
mesh_terms: D000483:Alleles; D045744:Cell Line, Tumor; D003550:Cystic Fibrosis / Q000235:genetics* / Q000473:pathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D056726:Genetic Association Studies / Q000379:methods; D005838:Genotype; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D007558:Italy; D009154:Mutation; D010641:Phenotype; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D044465:White People
chemical_list: C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator