Somatic DNA variability in human breast carcinoma.

Bkm-related probe 2[8], consisting mainly of GATA repeats, detects a hypervariable pattern of restriction fragment length polymorphisms in human DNA which is normally developmentally stable. However, specific somatic DNA variability was found in 53% (7/13) of human breast carcinomas, but not in eight cases of bladder carcinoma, when compared with leukocyte DNAs from the same patient under the same conditions. Certain of the restriction fragments detected carry both GATA-related sequences and sequences related to the M13 vector. Comparison of BstN1 digests of tumour and cognate leukocyte DNA revealed a further variable ethidium-stained restriction fragment class, not recognised by the probe, in 93% of breast and in 63% of bladder carcinomas.