title: A recurrent deep-intronic splicing CF mutation emphasizes the importance of mRNA studies in clinical practice.
abstract: BACKGROUND
  The identification by CFTR mRNA studies of a new deep-intronic splicing mutation, c.870-1113_1110delGAAT, in one patient of our series with mild CF symptoms and in three CF patients of an Italian study, led us to evaluate the mutation frequency and phenotype/genotype correlations.
  
  
  METHODS
  266 patients with CF and related disorders and having at least one undetected mutation, were tested at the gDNA level in three French reference laboratories.
  
  
  RESULTS
  In total, the mutation was found in 13 unrelated patients (5% of those already carrying a mutation) plus 4 siblings, including one homozygote and 12 heterozygotes having a severe CF mutation. The sweat test was positive in 10/14 documented cases, the diagnosis was delayed after 20 years in 9/15 and pancreatic insufficiency was present in 5/16.
  
  
  CONCLUSIONS
  c.870-1113_1110delGAAT should be considered as CF-causing with phenotype variability and overall delayed diagnosis. Its frequency highlights the potential of mRNA studies.
authors.affiliation: APHP, Groupe hospitalier Henri Mondor, Service de Biochimie-Génétique, Créteil, F-94010, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Costa
authors.forename: Virginie
authors.initials: V
authors.lastname: Pruliere-Escabasse
authors.forename: Alix
authors.initials: A
authors.lastname: de Becdelievre
authors.forename: Christine
authors.initials: C
authors.lastname: Gameiro
authors.forename: Lisa
authors.initials: L
authors.lastname: Golmard
authors.forename: Caroline
authors.initials: C
authors.lastname: Guittard
authors.forename: Laurence
authors.initials: L
authors.lastname: Bassinet
authors.forename: Thierry
authors.initials: T
authors.lastname: Bienvenu
authors.forename: Marie Des
authors.initials: MD
authors.lastname: Georges
authors.forename: Ralph
authors.initials: R
authors.lastname: Epaud
authors.forename: Eric
authors.initials: E
authors.lastname: Bieth
authors.forename: Irina
authors.initials: I
authors.lastname: Giurgea
authors.forename: Abdel
authors.initials: A
authors.lastname: Aissat
authors.forename: Alexandre
authors.initials: A
authors.lastname: Hinzpeter
authors.forename: Bruno
authors.initials: B
authors.lastname: Costes
authors.forename: Pascale
authors.initials: P
authors.lastname: Fanen
authors.forename: Michel
authors.initials: M
authors.lastname: Goossens
authors.forename: Mireille
authors.initials: M
authors.lastname: Claustres
authors.forename: André
authors.initials: A
authors.lastname: Coste
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Girodon
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007438:Introns / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics*; D055815:Young Adult
chemical_list: D012333:RNA, Messenger