A genetic association study of DNA methylation levels in the DRD4 gene region finds associations with nearby SNPs

作者:Docherty Sophia J*; Davis Oliver S P; Haworth Claire M A; Plomin Robert; D'Souza Ursula; Mill Jonathan
来源:Behavioral and Brain Functions, 2012, 8(1): 31.
DOI:10.1186/1744-9081-8-31

摘要

Background: Dopamine receptor D-4 (DRD4) polymorphisms have been associated with a number of psychiatric disorders, but little is known about the mechanism of these associations. DNA methylation is linked to the regulation of gene expression and plays a vital role in normal cellular function, with abnormal DNA methylation patterns implicated in a range of disorders. Recent evidence suggests DNA methylation can be influenced by cis-acting DNA sequence variation, that is, DNA sequence variation located nearby on the same chromosome. Methods: To investigate the potential influence of cis-acting genetic elements within DRD4, we analysed DRD4 promoter DNA methylation levels in the transformed lymphoblastoid cell-line DNA of 89 individuals (from 30 family-trios). Five SNPs located +/-10kb of the promoter region were interrogated for associations with DNA methylation levels. Results: Four significant SNP associations were found with DNA methylation (rs3758653, rs752306, rs11246228 and rs936465). The associations of rs3758653 and rs936465 with DNA methylation were tested and nominally replicated (p-value < 0.05) in post-mortem brain tissue from an independent sample (N = 18). Interestingly, the DNA methylation patterns observed in post-mortem brain tissue were similar to those observed in transformed lymphoblastoid cell line DNA. Conclusions: The link reported between DNA sequence and DNA methylation offers a possible functional role to seemingly non-functional SNP associations. DRD4 has been implicated in several psychiatric disease phenotypes and our results shed light upon the possible mode of action of SNP associations in this region.

  • 出版日期2012-6-12