title: Comparison of the CFTR mutation spectrum in three cohorts of patients of Celtic origin from Brittany (France) and Ireland.
abstract: This study aims to compare the spectrum of the mutations identified in the gene responsible for cystic fibrosis in three cohorts of patients of Celtic origin from Brittany and Ireland. It included 389 patients from Brittany, 631 from Dublin and 139 from Cork. The CFTR gene analysis relied on the detection of the most common mutations, followed by a complete gene scanning using DGGE or D-HPLC. High mutation detection rates were obtained in each cohort: 99.6%, 96.8%, and 96.0% respectively. A high frequency of the c.1652_1655 del3 mutation (F508del: 74.8% to 81.3%) and of the "Celtic" mutation (c.1784G>A (G551D): 3.7% to 9.7%) was observed in each population. Apart from this, the mutation spectrums differed. In Brittany, the most common abnormalities were: c.1078delT (3.6%), c.4041C>G (N1303K: 1.4%), c.2670G>A (W846X(2): 1.0%) and c.1717-1G>A (1.0%), whereas in the cohort of Dublin, the main mutations were: c.482G>A (R117H: 3.0%), c.1811G>C (R560T: 2.4%) and c.621+1G>T (1.7%). Finally, in the Cork area, only the c.482G>A mutation (R117H) reached a frequency of 1%. Two previously-unreported mutations were identified in the Dublin cohort: c.2623-2A>G and c.3446T>G (M1105R). This collaborative study highlights the similarities of the CFTR alleles in the Breton and Irish populations, but also the disparities that exist between these populations, despite their common origin. Each population has its own history, with its mixture of founder effects and genetic drifts, which are at the origin of the current mutation distribution. The molecular study of the CFTR gene provides new tools for retracing European populations' histories.
authors.affiliation: INSERM EMI 01-15, Laboratoire de Génétique Moléculaire, Brest, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Scotet
authors.forename: David E
authors.initials: DE
authors.lastname: Barton
authors.forename: James B G
authors.initials: JB
authors.lastname: Watson
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Audrézet
authors.forename: Trudi
authors.initials: T
authors.lastname: McDevitt
authors.forename: Shirley
authors.initials: S
authors.lastname: McQuaid
authors.forename: Cathy
authors.initials: C
authors.lastname: Shortt
authors.forename: Marc
authors.initials: M
authors.lastname: De Braekeleer
authors.forename: Claude
authors.initials: C
authors.lastname: Férec
authors.forename: Cédric
authors.initials: C
authors.lastname: Le Maréchal
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution / Q000235:genetics; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000235:genetics; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005602:France / Q000453:epidemiology; D005787:Gene Frequency / Q000235:genetics; D005828:Genetics, Population / Q000379:methods; D005838:Genotype; D006801:Humans; D007494:Ireland / Q000453:epidemiology / Q000208:ethnology; D009154:Mutation
chemical_list: C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator