title: Genomics of Hereditary Colorectal Cancer: Lessons Learnt from 25 Years of the Singapore Polyposis Registry.
abstract: BACKGROUND
  The Singapore Polyposis Registry (SPR) was established in 1989 in Singapore General Hospital (SGH). The aims were to provide a central registry service to facilitate identification, surveillance and management of families and individuals at high risk of colorectal cancer.
  
  
  METHODS
  This is a review of published literature in the department.
  
  
  RESULTS
  The registry currently has 253 families with several genetic conditions-93 familial adenomatous polyposis (FAP) families, 138 Amsterdam-criteria positive presumed Lynch syndrome (LS) families, 12 families with Peutz Jeghers syndrome, 2 families with Cowden's syndrome, and 8 families with hereditary mixed polyposis syndrome (HMPS). There are also 169 families with a strong family history of colorectal cancer but no abnormal genes yet identified. In FAP, a diagnostic tool developed has allowed a 94% local APC germline detection rate in FAP families. Knowledge obtained studying the phenotype of FAP patients has allowed better choice of surgery between ileal pouch anal anastomosis (IPAA) against an ileal-rectal anastomosis (IRA). In LS, our review has noted a highly heterogenous mutational spectrum and novel variants made up 46.7% (28/60) of all variants identified in this cohort. This may suggest that our Southeast Asian ethnic groups have distinct mutational variants from Western populations. Pathogenic mutations were only confined to MLH1 and MSH2, and identified in 28.8% of families.
  
  
  CONCLUSIONS
  The impact of predictive gene testing for hereditary cancer risk in clinical practice has allowed evolution of care. Risk-reducing surgery and aggressive surveillance allows reduction in morbidity and mortality of patients. The SPR will continue to grow and improve outcomes in hereditary colorectal cancer patients and families.
authors.affiliation: Department of Colorectal Surgery, Singapore General Hospital, Singapore.
authors.forename: Min Hoe
authors.initials: MH
authors.lastname: Chew
authors.forename: Wah Siew
authors.initials: WS
authors.lastname: Tan
authors.forename: Yanqun
authors.initials: Y
authors.lastname: Liu
authors.forename: Peh Yean
authors.initials: PY
authors.lastname: Cheah
authors.forename: Carol Tt
authors.initials: CT
authors.lastname: Loi
authors.forename: Choong Leong
authors.initials: CL
authors.lastname: Tang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics / Q000601:surgery; D019468:Disease Management; D005260:Female; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D008297:Male; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics*; D009154:Mutation; D009386:Neoplastic Syndromes, Hereditary / Q000145:classification / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics / Q000601:surgery; D009687:Nuclear Proteins / Q000235:genetics*; D012042:Registries / Q000706:statistics & numerical data; D012846:Singapore / Q000453:epidemiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein