Detection of Aberrant Methylation of the p15INK4B Gene Promoter

The 5’ promoter regions of some genes contain CpG-rich areas, known as CpG islands. Methylation of the cytosines in these CpG dinucleotides by DNA methyltransferase generating 5-methylcytosine has important regulatory effects on gene expression (). Almost all gene-associated CpG islands are protected from methylation on autosomal chromosomes (). by contrast, DNA methylation of CpG islands normally occurs in selected imprinted genes () and genes on the inactive X-chromosome of females (), and may play an important role during normal embryonic development.