ANALYSES OF LINKAGE TO 17Q11-Q23 IN 3 FRENCH HEREDITARY NONPOLYPOSIS COLON-CANCER FAMILIES

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dom inant disease, accounting for approximately 6% of colorectal cancers. We performed linkage analyses with the aim of proving or excluding the existence of a susceptibility locus on 17q. Three HNPCC families (102 collected members, 25 colorectal cancers, 9 other cancers and 6 color ectal adenomas) were studied with 7 polymorphic DNA markers Mfd15, THR A 1, D17S800, D17S855, Mfd 188, 42D6, 46E6 localized in the 17q11-q23 region. After in vitro enzymatic amplification, the different alleles were separated by classic vertical poly-acrylamide gel electrophoresis or analyzed with the automatic sequencing machine 373A (Applied Biosy stems). Results showed that none of the 7 studied markers of the chrom osome 17q were linked to the HNPCC disease.