Patent ID: 7148016

Claim:
A method of screening for hereditary colorectal cancer or a predisposition to hereditary colorectal cancer in an organism, said screening method comprising: (a) isolating a biological sample containing normal cells from said organism; (b) preparing a lysate of said normal cells; (c) preparing a protein extract from said lysate of said normal cells; (d) immunologically quantitating the levels of two or more full-length subject proteins in said protein extract of said normal cells, wherein said subject proteins are selected from the group consisting of MLH1, MSH2, MSH6, PMS1, and APC proteins; (e) calculating the ratio of the level of one full-length subject protein in said normal cells, to the level of one or more of the other full-length subject proteins in said normal cells; and (f) determining whether the ratio or ratios calculated in step (e) reflects or reflect about a 50% decrease from the normal level of any of the subject proteins for which a wild-type level was immunologically quantitated; (g) whereby if the ratio or ratios calculated in step (e) indicates or indicate that there is about a 50% decrease from the normal level of one of the full-length subject proteins in said normal cells, that the subject organism has hereditary colorectal cancer or has a predisposition to hereditary colorectal cancer.