A rapid and cell-free assay to test the activity of lynch syndrome-associated MSH2 and MSH6 missense variants

Hum Mutat. 2012 Mar;33(3):488-94. doi: 10.1002/humu.22000. Epub 2011 Dec 29.


Lynch syndrome (LS) is an autosomal dominant disorder that predisposes to colon, endometrial, and other cancers. LS is caused by a heterozygous germline mutation in one of the DNA mismatch repair (MMR) genes. A significant proportion of all mutations found in suspected LS patients comprises single amino acid alterations. The pathogenicity of these variants of uncertain significance (VUS) is difficult to assess, precluding diagnosis of carriers and their relatives. Here we present a rapid cell-free assay to investigate MMR activity of MSH2 or MSH6 VUS. We used this assay to analyze a series of MSH2 and MSH6 VUS, selected from the Leiden Open Variation Database. Whereas a significant fraction of the MSH2 VUS has lost MMR activity, suggesting pathogenicity, the large majority of the MSH6 VUS appears MMR proficient. We anticipate that this assay will be an important tool in the development of a comprehensive and widely applicable diagnostic procedure for LS-associated VUS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Assay / methods*
  • Blotting, Western
  • Colorectal Neoplasms, Hereditary Nonpolyposis / genetics*
  • Colorectal Neoplasms, Hereditary Nonpolyposis / metabolism*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Humans
  • MutS Homolog 2 Protein / genetics*
  • MutS Homolog 2 Protein / metabolism*
  • Mutation, Missense / genetics
  • Polymerase Chain Reaction


  • DNA-Binding Proteins
  • G-T mismatch-binding protein
  • MSH2 protein, human
  • MutS Homolog 2 Protein