CUMULATIVE REGIONAL ALLELOTYPING OF HUMAN BREAST CARCINOMAS - APPLICATION TO CHROMOSOME-1 TO CHROMOSOME-5

We have analyzed losses of heterozygosity (LOH) at markers from chromo somes 1, 2, 4 and 5 in a panel of 53 consecutive breast carcinomas. To gether with a parallel analysis of LOH at chromosome 3, this allowed t he identification of twenty-one regions of LOH. In contrast, in a comp arative analysis of chromosome X, no region of loss could be defined. Cumulative regional allelotyping of 38 tumors with 71 markers from the five autosomes (37% of the genome) enabled the study of the respectiv e distribution of regions of frequent loss, to identify associations o f regions of LOH, and to distinguish tumors frequently affected by LOH such as lobular carcinomas.