Table 2

 Mutations detected in 27 index MTS patients

Patient numberGeneExonMutationEffectMSI statusMMR protein loss at IHC
*Mutation (according to current nomenclature) in this patient diagnosed with MTS or suspected MTS was reported previously4,15,19,20; †novel mutation not listed in the ICG-HNPCC database ( IHC, immunohistochemistry; ND, not done; NT, no tumour tissue available.
555 (MTS-23) MSH2 1 to 6Deletion of exons 1–6Large deletionMSI-HND
554 (MTS-21) MSH2 1c.145delG†FrameshiftMSI-HND
130 MSH2 2c.289_290ins22bp* (c.268–289dup)FrameshiftMSI-HMSH2
593 MSH2 2c.289C>TQ97XNTNT
435 (MTS-10) MSH2 3c.380_381delAT*FrameshiftMSI-HNT
162 MSH2 3c.478C>T†Q160XMSI-HMSH2
726 (ST-62) MSH2 3c.592_593insG†FrameshiftNDND
278 MSH2 5c.862C>T*Q288XMSI-HMSH2
122 MSH2 5c.942+3 A>TAlteration of splicingMSI-HNT
765 (ST-63) MSH2 7c.1165C>TR389XNDMSH2
535 MSH2 7c.1189C>TQ397XMSI-HMSH2
788 (ST-33) MSH2 8c.1373T>GL458XNDMSH2
631 (MTS-18) MSH2 9, 10Deletion of exons 9, 10†Large deletionMSI-HNT
810 MSH2 10c.1571G>CR524PMSI-HNone
MTS-2a MSH2 10c.1576delA*FrameshiftMSI-HND
398 (MTS-24) MSH2 10c.1578delC†FrameshiftMSI-HMSH2
132 MSH2 11c.1676delA*FrameshiftMSI-HNT
167 MSH2 11c.1700_1704delAAACA*FrameshiftMSI-HMSH2
133 MSH2 12c.1809delT*FrameshiftMSI-HMSH2
655 (ST-29) MSH2 12c.2005+2T>C†Alteration of splicingNDND
851 (MTS-8) MSH2 13c.2015delT*FrameshiftMSI-HNT
62 MSH2 13c.2090 G>T*C697FMSI-HMSH2
667 (ST-28) MSH2 13c.2131C>TR711XMSI-HMSH2
628 (ST-27) MSH2 14c.2228C>GS743XMSI-HMSH2
762 MSH2 15, 16Deletion of exons 15, 16†Large deletionMSI-HMSH2
MTS-9 MLH1 2c.150_151insT*FrameshiftMSI-HND
MTS-14 MLH1 16c.1884_1888delGGAAA*FrameshiftMSI-HND