A NOVEL MSPI PCR-RFLP IN THE HUMAN CYTOSINE 5-METHYLTRANSFERASE GENE - LACK OF RELEVANCE FOR MALIGNANT LYMPHOPROLIFERATIVE DISEASE AND BREAST-CANCER

Two alternate allelic forms of human cytosine 5-methyltransferase, 5-M T I and 5-MT II, which differ by the absence or presence of an introni c MspI recognition sequence, have been recognised, The polymorphic reg ion was localised using a series of subprobes prepared upon MspI diges tion of the 2.5-kb cDNA probe (hmt-2.5). A PCR-based method was then d eveloped for rapid 5-MT genotyping, The gene and phenotype frequencies of 5-MT I and 5-MT II were not significantly different in genomic DNA samples from a series of non-Hodgkin's lymphomas and breast cancer ca ses compared with DNA from normal subjects, Allelism of 5-MT allows ne w approaches to the assessment of variation in gene copy number of 5-M T in different types of neoplasia.