Increased methylation of DNA

Methylation is the addition of a methyl group (CHy) to a molecule. In this case the methyl group is added to the cytosine bases of DNA. Methylation normally inhibits the transcription of genes in two ways. o preventing the binding of transcriptional factors to the DNA o attracting proteins that condense the DNA-histone complex (by inducing deacetylation of the histones) making the DNA inaccessible to transcription factors.