Article open access publication

CACNA1C hypermethylation is associated with bipolar disorder

Translational Psychiatry, Springer Nature, ISSN 2158-3188

Volume 6, 6, 2016

DOI:10.1038/tp.2016.99, Dimensions: pub.1015597987, PMC: PMC4931616, PMID: 27271857,

Authors

Starnawska, A (1) (2)
Demontis, D (1) (2)
Pen, A (1)
Hedemand, A (1) (2)
Nielsen, A L (1) (2)
Staunstrup, N H (1) (2)
Grove, J (1) (2)
Als, T D (1) (2)
Jarram, A (3)
Mors, O (2) (4)
Børglum, A D (1) (2)
Nyegaard, M * (1) (2)

* Corresponding author

Affiliations

Organisations

  1. (1) Aarhus University, grid.7048.b, AU
  2. (2) Lundbeck Foundation, grid.452548.a
  3. (3) University College London, grid.83440.3b
  4. (4) Aarhus University Hospital, grid.154185.c, Central Denmark Region

Countries

Denmark

United Kingdom

Continents

Europe

Description

The CACNA1C gene, encoding a subunit of the L-type voltage-gated calcium channel is one of the best-supported susceptibility genes for bipolar disorder (BD). Genome-wide association studies have identified a cluster of non-coding single-nucleotide polymorphisms (SNPs) in intron 3 to be highly associated with BD and schizophrenia. The mechanism by which these SNPs confer risk of BD appears to be through an altered regulation of CACNA1C expression. The role of CACNA1C DNA methylation in BD has not yet been addressed. The aim of this study was to investigate if CACNA1C DNA methylation is altered in BD. First, the methylation status of five CpG islands (CGIs) across CACNA1C in blood from BD subjects (n=40) and healthy controls (n=38) was determined. Four islands were almost completely methylated or completely unmethylated, while one island (CGI 3) in intron 3 displayed intermediate methylation levels. In the main analysis, the methylation status of CGI 3 was analyzed in a larger sample of BD subjects (n=582) and control individuals (n=319). Out of six CpG sites that were investigated, five sites showed significant hypermethylation in cases (lowest P=1.16 × 10(-7) for CpG35). Nearby SNPs were found to influence the methylation level, and we identified rs2238056 in intron 3 as the strongest methylation quantitative trait locus (P=2.6 × 10(-7)) for CpG35. In addition, we found an increased methylation in females, and no difference between bipolar I and II. In conclusion, we find that CACNA1C methylation is associated with BD and suggest that the regulatory effect of the non-coding risk variants involves a shift in DNA methylation.

Funders

Funders and Grants

Links & Metrics

NORA University Profiles

Aarhus University

Danish Open Access Indicator

2016: Realized

Research area: Medicine

Dimensions Citation Indicators

Times Cited: 20

Field Citation Ratio (FCR): 6.84

Relative Citation ratio (RCR): 0.72

Open Access Info

Pure Gold