Determination of Loss of Heterozygosity Using Polymerase Chain Reaction

Loss of heterozygosity (LOH) is being detected with increasing frequency in a wide variety of human tumors (1 -10 ). Frequent LOH at a given chromosomal locus implies the existence of a tumor suppressor gene that is important in the pathogenesis of the particular cancer under study. LOH is believed to represent inactivation of one allele of a tumor suppressor gene by chromosomal or subchromosomal deletion. LOH studies have led to the isolation of new tumor suppressor genes (11 -13 ). They have also pinpointed known tumor suppressor genes that may be significant in specific types of cancer (14 ,15 ).