The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here:

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Åke Borg

Åke Borg

Principal investigator

Åke Borg

Merged testing for colorectal cancer syndromes and re-evaluation of genetic variants improve diagnostic yield : Results from a nationwide prospective cohort


  • Sara Svensson
  • Theofanis Zagoras
  • Christos Aravidis
  • Marie Stenmark Askmalm
  • Erik Björck
  • Åke Borg
  • Ekaterina Kuchinskaya
  • Mef Nilbert
  • Margareta Nordling
  • Anna Rohlin
  • Gustav Silander
  • Kristina Lagerstedt-Robinson
  • Samuel Gebre-Medhin

Summary, in English

Approximately 5% of patients with colorectal cancer (CRC) have a Mendelian predisposition for the disease. Identification of the disease-causing genetic variant enables carrier testing and tailored cancer prevention within affected families. To determine the panorama and genetic variation of Mendelian CRC syndromes among referrals at the cancer genetics clinics in Sweden, 850 patients clinically selected for CRC genetic investigation were included in a prospective study that tested for all major hereditary polyposis and nonpolyposis CRC conditions. Genetically defined syndromes were diagnosed in 11% of the patients. Lynch syndrome was predominant (n = 73) followed by familial adenomatous polyposis (n = 12) and MUTYH-associated polyposis (n = 8); the latter of which two patients presented with CRC before polyposis was evident. One patient with a history of adolescent-onset CRC and polyposis had biallelic disease-causing variants diagnostic for constitutional mismatch repair deficiency syndrome. Post-study review of detected variants of unknown clinical significance (n = 129) resulted in the reclassification of variants as likely benign (n = 59) or as diagnostic for Lynch syndrome (n = 2). Our results reveal the panorama of Mendelian CRC syndromes at the cancer genetics clinics in Sweden and show that unified testing for polyposis and nonpolyposis CRC conditions as well as regular reexamination of sequence data improve the diagnostic yield.


  • Division of Clinical Genetics
  • Paediatrics (Lund)
  • Breastcancer-genetics
  • Familial Breast Cancer
  • LUCC: Lund University Cancer Centre
  • EpiHealth: Epidemiology for Health

Publishing year







Genes Chromosomes and Cancer





Document type

Journal article


John Wiley & Sons Inc.


  • Cancer and Oncology
  • Medical Genetics


  • colorectal cancer
  • genetic testing
  • hereditary
  • polyposis
  • syndrome
  • variant classification



Research group

  • Familial Breast Cancer


  • ISSN: 1045-2257