Patent ID: 7662595

Claim:
A method for detecting a high level microsatellite instability (MSI-H) phenotype in a human test tissue sample, comprising the steps: (a) obtaining a human test tissue sample, said test tissue sample comprising nucleic acids, wherein said test tissue sample is isolated from a tumor selected from the group consisting of tumors of the colorectal tract, colorectal carcinoma, colorectal adenoma, colorectal polyps, tumors of the gastrointestinal tract, carcinoma of the small intestine, polyps of the small intestine, endometrial tumors, endometrial carcinoma, endometrial hyperplasia, ovarian tumors, and urothelial tumors; (b) detecting the allele length of the CAT25 repeat in said nucleic acid; wherein the CAT25 repeat is the T25 (SEQ ID NO: 96) mononucleotide repeat, in exon 11 of the 3′-untranslated region of the Caspase 2 (CASP2) gene, amplifiable with a primer pair that is comprised of a first primer selected from the group consisting of SEQ ID NO: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 and 21, and a second primer selected from the group consisting of SEQ ID NO: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, and 22; (c) detecting the presence of a difference of the allele length of the CAT25 repeat in said human test tissue sample in comparison with the main allele lengths of the CAT25 repeat present in human control tissue samples that do not have an MSI-H phenotype; and (d) correlating the presence of a difference in the allele length of the CAT25 repeat with the presence of a MSI-H phenotype in said tissue.