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-MT I and 5-MT II, which differ by the absence or presence of an intronic MspI recognition sequence, have been recognised, The polymorphic region was localised using a series of subprobes prepared upon MspI digestion of the 2.5-kb cDNA probe (hmt-2.5). A PCR-based method was then developed 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 cases compared with DNA from normal subjects, Allelism of 5-MT allows new approaches to the assessment of variation in gene copy number of 5-MT in different types of neoplasia.