A c-myc gene variant without exon 1 and with an abnormal methylation pattern inherited in a woman with no evidence of malignancy

A c-myc DNA with a deletion which includes 5′ flanking, exon 1 and intron I sequences has been found in normal white blood cells of a mother and one daughter in a Northern Italian family. In addition, the degree of methylation of specific CCGG sites in the truncated DNA is lower in both mother and daughter than that found in normal DNA. It is of interest that deletions of the first exon and hypomethylation of the c-myc gene have usually been observed only in some neoplasias. However, our results demonstrate that the c-myc trun-cated DNA with the abnormal methylation pattern here reported is a genomic variant which by itself is not related to neoplastic transformation.