title: Keratin 8 Y54H and G62C mutations are not associated with inflammatory bowel disease.
abstract: BACKGROUND
  Keratin 8 is a major component of intermediate filaments in single-layered epithelia of the gastrointestinal tract. Keratin 8 deficient mice display signs of colitis and diarrhoea characteristic for inflammatory bowel disease. Very recently, two keratin 8 mutations, Y54H and G62C, were identified.
  
  
  OBJECTIVE
  We investigated if these keratin 8 missense mutations were associated with inflammatory bowel disease.
  
  
  METHODS
  In total, 217 German patients with Crohn' s disease, 131 German patients with ulcerative colitis, and 560 German control subjects were enrolled in this study.
  
  
  METHODS
  Samples were analysed by PCR amplification and subsequent melting curve analysis using fluorescence resonance energy transfer probes.
  
  
  RESULTS
  The G62C mutation was detected in five (2.3%) patients presenting with Crohn's disease and in three (2.3%) with ulcerative colitis. In comparison, 9 (1.6%) out of 560 controls were heterozygous for this mutation. No patient or control was homozygous for this mutation. Patients carrying one mutant allele did not show any noticeable characteristics in their corresponding phenotype. In contrast, the Y54H mutation was observed in neither any of the 348 patients with inflammatory bowel disease nor in any control subject.
  
  
  CONCLUSIONS
  Our data indicate that both keratin 8 mutations, G62C and Y54H, do not play a relevant pathogenic role in inflammatory bowel disease.
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Universitätsmedizin Berlin, Charité, Campus Mitte, Schumannstrasse 20/21, D-10117 Berlin, Germany. carsten.buening@charite.de
authors.forename: C
authors.initials: C
authors.lastname: Büning
authors.forename: J
authors.initials: J
authors.lastname: Halangk
authors.forename: A
authors.initials: A
authors.lastname: Dignass
authors.forename: J
authors.initials: J
authors.lastname: Ockenga
authors.forename: P
authors.initials: P
authors.lastname: Deindl
authors.forename: R
authors.initials: R
authors.lastname: Nickel
authors.forename: J
authors.initials: J
authors.lastname: Genschel
authors.forename: O
authors.initials: O
authors.lastname: Landt
authors.forename: H
authors.initials: H
authors.lastname: Lochs
authors.forename: H
authors.initials: H
authors.lastname: Schmidt
authors.forename: H
authors.initials: H
authors.lastname: Witt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D005260:Female; D006579:Heterozygote; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics*; D053533:Keratin-8; D007633:Keratins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense
chemical_list: C426203:KRT8 protein, human; D053533:Keratin-8; D007633:Keratins