King's College London Scientists from the Institute of Psychiatry (IoP), King’s College London, claims to have recognized several new areas of the genome where chemical alterations included in regulating gene expression may be impacted by either genetic variation or the parental origin of that certain stretch of DNA.

This seems to oppose preceding supposition that epigenetic signals could usually be equivalent across both copies of a known area of the genome, except at a minute amount of identified imprinted genes. Sequencing the genome was alleged to be only the primary step in the pursuit to comprehend how genes are expressed and controlled.

Epigenetics is claimed to be the study of alterations to gene function, conventionally thought to take place independently of the DNA sequence. The epigenome apparently sits above the DNA sequence and delivers a second layer of information, controlling numerous genomic functions, counting when and where genes are switched on or off. Supposedly, one of the best comprehended epigenetic mechanisms may be DNA methylation, a chemical modification to DNA that could hinder with gene expression.

In the first quantitative genomic review of allele-specific DNA methylation, scientists apparently utilized receptive high-throughput technology to identify proof for distorted gene DNA methylation across both alleles and copies of the DNA sequence at roughly 1 million sites in the genome.

Lead researcher Dr Jonathan Mill, Medical Research Council Social Genetic, Developmental and Psychiatry Centre at the IoP, commented, “Interestingly, we found numerous examples where DNA methylation was not equal across alleles – in some instances this depended upon genotype, and in other cases it depended upon which parent that allele was inherited from. Our data show that allele-specific DNA methylation is a widespread phenomenon with potentially over 35,000 such sites occurring across the genome. It appears that a spectrum of skewing is likely, differing between individuals and across tissues.

He mentioned that these findings impact upon their understanding about the origin of biological variation and have implications for genetic studies of complex disease including most psychiatric conditions.

He also added that since DNA methylation can also be influenced by various environmental factors, the variation they have uncovered provides a potential substrate for interactions between nature and nurture.