A novel highly informative polyA microsatellite on the telomeric side of the INK4a/ARF locus

The INK4a/ARF locus encodes two cell cycle-regulatory proteins, p16(INK4a)and p14(ARF). Inactivation of the p16(INK4a)(MTS1) tumor suppressor gene by mutations, promoter methylation or gene deletions is a common event in the development of many different human tumors. The present report describes a novel polyA mononucleotide repeat situated 7.2 kb on the telomeric side of the INK4a/ARF locus. This highly polymorphic microsatellite marker (heterozygote frequency: 0.78) proved to be efficient for p16 allele loss and microsatellite instability analyses in human colon cancer.