Catharina Larsson

Loss of constitutional heterozygosity in human cancer: A practical approach

Publisher Summary This chapter discusses a practical approach for the loss of constitutional heterozygosity in human cancer. First observed in rare heritable cancer syndromes and eliminating genes that exert cellular control functions, “genetic losses” have now also been found in frequent and noninherited cancers as the initial step of tumorigenesis and contributing to tumor progression. Screening for genetic losses is, therefore, a generally applied method for the characterization of cancer. Apart from methods related to classical cytogenetics, new molecular tools developed in the past decade have dramatically refined the resolution and facilitated the characterization of the tumor cell genotype. DNA markers have been developed that distinguish between the alleles of homologous chromosomes, enabling the investigator to monitor losses of single alleles and to determine their parental origin. Thus, the detection of “loss of heterozygosity” (LOH) has become a widespread method in cancer research and in the search for the specific genes involved in the genesis and progression of several tumors.