Hypermethylation of the M27beta (DXS255) locus in chronic B-cell leukaemia.

We have investigated the methylation status of the M27beta (DXS255) locus in 21 female patients with chronic B-cell leukaemia and in 20 normal controls. DNA was digested with Pst1 and then with the methylation sensitive enzyme HpaII and probed with the M27beta probe. Eight patients (38%) showed hypermethylation of the M27beta locus which was not seen in any of the normal controls. Hypermethylation of the M27beta locus has also been found in acute myeloid leukaemia, acute lymphocytic leukaemia and lymphoma, suggesting that hypermethylation of the M27beta locus is associated with the leukaemic process.