A new laboratory method improves the accuracy of current genetic diagnostic tests for colon cancer by detecting defective genes otherwise "masked" when one copy of the gene in question is normal. The technique may also be used to enhance the accuracy of diagnostic tests for a wide range of inherited diseases, including other forms of cancer and neurological disorders. Humans carry two copies of each gene, one of which is inherited from the mother and one from the father. One of the weaknesses of genetic testing is that a normal gene can mask the presence of the defective or missing gene. In instances where masking occurs, the diagnostic tests will either not detect the genetic defect or will prove far less sensitive to it. "We have overcome the problem of the normal allele masking the mutant allele by simply separating the alleles and analyzing them independently," explained Bert Vogelstein, a Howard Hughes Medical Institute investigator at The Johns Hopkins University Oncology Center. In technical terms, the technique involves conversion of the cells' paired-chromosome state of "diploidy" to a single chromosome state of "haploidy," said Vogelstein. Ann's NOTE: Hopefully this will resolve the (former) confusion of results. Study shows diagnoses at earlier stages April 2000 JNCI, 7/18/01 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.