title: Clinical subtypes and molecular characteristics of serrated polyposis syndrome.
abstract: OBJECTIVE
  We investigated clinical and molecular differences between the different phenotypes of serrated polyposis syndrome (SPS) and the frequency of mutations in BRAF or KRAS in polyps from patients with SPS.
  
  
  METHODS
  We collected data on clinical and demographic characteristics of 50 patients who fulfilled the criteria for SPS. Polymerase chain reaction and sequence analysis were used to identify BRAF and KRAS mutations in 432 polyps collected from 37 patients; we analyzed CpG island methylator phenotypes in 272 of these polyps.
  
  
  RESULTS
  Fifteen patients (30%) had type 1 SPS and 35 had type 2 SPS. There were no significant differences in age at diagnosis, sex, smoking frequency, body mass index, or colorectal cancer predisposition between groups of patients, or in the pathologic or molecular characteristics of their polyps. A familial history of colorectal cancer or colonic polyps was reported more frequently by patients with type 2 SPS. BRAF mutations were found in 63% of polyps and KRAS mutations were found in 9.9%; 43.4% of polyps had the CpG island methylator phenotype-high phenotype. A per-patient analysis revealed that all patients had a BRAF or KRAS mutation in more than 25% of their polyps; 84.8% of patients had a mutation in BRAF or KRAS in more than 50% of their polyps.
  
  
  CONCLUSIONS
  Except for a greater likelihood of familial history of colorectal cancer or colonic polyps in patients with type 2 SPS, we found no significant demographic, pathologic, or molecular differences between types 1 and 2 SPS. All patients had a BRAF or KRAS mutation in at least 25% of their polyps.
authors: Unidad de Investigación, Hospital General Universitario de Alicante, Alicante, Spain.
authors: Carla
authors: C
authors: Guarinos
authors: Cristina
authors: C
authors: Sánchez-Fortún
authors: María
authors: M
authors: Rodríguez-Soler
authors: Lucía
authors: L
authors: Pérez-Carbonell
authors: Cecilia
authors: C
authors: Egoavil
authors: Miriam
authors: M
authors: Juárez
authors: Anna
authors: A
authors: Serradesanferm
authors: Luis
authors: L
authors: Bujanda
authors: Fernando
authors: F
authors: Fernández-Bañares
authors: Joaquín
authors: J
authors: Cubiella
authors: Luisa
authors: L
authors: de-Castro
authors: Ana
authors: A
authors: Guerra
authors: Elena
authors: E
authors: Aguirre
authors: Alberto
authors: A
authors: Herreros-de-Tejada
authors: Xavier
authors: X
authors: Bessa
authors: Maite
authors: M
authors: Herráiz
authors: José-Carlos
authors: JC
authors: Marín-Gabriel
authors: Judith
authors: J
authors: Balmaña
authors: Miriam
authors: M
authors: Cuatrecasas
authors: Francesc
authors: F
authors: Balaguer
authors: Antoni
authors: A
authors: Castells
authors: José-Luis
authors: JL
authors: Soto
authors: Cristina
authors: C
authors: Alenda
authors: Artemio
authors: A
authors: Payá
authors: Rodrigo
authors: R
authors: Jover
mesh_terms: D011125:Adenomatous Polyposis Coli / Q000235:genetics* / Q000473:pathology*; D000328:Adult; D000368:Aged; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D017422:Sequence Analysis, DNA; D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins