Methylation profile of SNRPN gene and its correlation with weight and chronological age.

Genomic imprinting is an important epigenetic phenomenon, wherein genes or gene clusters are marked by DNA methylation during gametogenesis. This plays a major role in several functions of normal cells, including cell differentiation, X chromosome inactivation, and the maintenance of chromatin structure, in mammalian development. The aim of this study was to investigate the possible differences in SNRPN gene methylation profiles in non-obese and obese individuals, and in children and adults. Our results did not reveal any statistical correlations between the DNA methylation profiles of the SNRPN gene in children or adult obese and non-obese groups. However, a comparison of the methylation levels with the chronological age revealed statistically significant differences between the means of methylation in adults and children (46.20 +/- 5.88 and 39.40 +/- 2.87, respectively; P < 0.001). Pearson's correlation analysis indicated a positive association between the level of DNA methylation and the chronological age (R-2 = 0.326; P < 0.001). Therefore, we concluded that the methylation profile of the SNRPN promoter (in blood) is not a useful biomarker for determining the predisposition of an individual to obesity. Additionally, we have confirmed that SNRPN methylation increases with age, which raises further questions regarding the role of SNRPN expression during the aging process.