LOSS OF HETEROZYGOSITY ON 17P IN HUMAN BREAST CARCINOMAS - DEFINING THE SMALLEST COMMON REGION OF DELETION

The marker DI7S5. mapping to the short arm of chromosome 17. was recently reported by us and others to undergo frequent heterozygous deletion in human primary breast carcinomas. implicating the presence of a tumor suppressor gene in this region. To narrow down the location of this gene more precisely. we have performed a deletion-mapping study in an extended series of 78 breast carcinomas, using nine polymorphic markers for the short arm and two polymorphic markers for the long arm of chromosome 17. Partial allele losses on 17p were observed in nine cases, which, taken together, suggest that the target gene for the deletions maps to the region extending between the markers D17S5(17pl3.3)andD17S67(17pl2). © 1990 S. Karger AG, Basel.