Role of DNA methylation in human age prediction.

DNA methylation (DNAm) is a fundamental biochemical modification which occurs over the lifespan of an individual and it is a significant component in the aging process. Methylation level of CpG sites plays an important role in finding the age of a person. Different approaches were used to extract age-related CpG (AR-CpG) sites for developing age-prediction models because the level of methylation is directly related to age for some CpG sites. Several age prediction models have been developed over the past few years and most of these models were based on regression techniques. This paper reviews and analyzes age-prediction models developed using methylated data. The first section introduces the problem of aging in humans. In the next section, the concept of DNA methylation is described in detail. Thereafter, DNA methylation based age-prediction methods are discussed. In addition to this, a summary of all these methods is also provided. Finally, some limitations of the current research along with future directions are given.