Table 4

Constitutional mutations detected in HNPCC families registered between 1984 and 1998

Family IDGeneDNA changeEffectImmunohistochemistry
HNPCC, hereditary non-polyposis colorectal cancer.
Total families observed 34; tested 24; positive 6 (25%).
2 hMSH2 4 bp del exon 7Truncated proteinNo MSH2 protein expression
10 hMSH2 AT intron 6Truncated proteinNo MSH2 protein expression
39 hMSH2 del A exon 16Truncated proteinNormal expression
41 hMSH6 del A exon 19Truncated proteinNo MSH6 protein expression
1 hMLH1 ins T exon 19Protein elongationNo MLH1 protein expression
20 hMLH1 ins T exon 19Protein elongationNo MLH1 protein expression