Epigenome-wide DNA methylation in obsessive-compulsive disorder

Area of Science:

• Genetics and Epigenetics
• Neuroscience
• Psychiatry

Background:

• Altered DNA methylation is observed in candidate genes of adult obsessive-compulsive disorder (OCD).
• Epigenome-wide DNA methylation studies in OCD are limited, with only one prior study in a Chinese population.

Purpose of the Study:

• To conduct the first epigenome-wide association study (EWAS) of DNA methylation in adult OCD patients of European ancestry.
• To identify novel quantitative trait methylation sites (QTMs) associated with OCD.
• To explore the potential of identified QTMs as peripheral epigenetic markers for OCD risk.

Main Methods:

• An epigenome-wide association study (EWAS) was performed using the Illumina MethylationEPIC BeadChip.
• The study included 76 adult OCD patients and 76 sex- and age-matched healthy controls of European ancestry.
• Quality control was applied, resulting in a final sample of 68 patients and 68 controls for analysis.

Main Results:

• Nine epigenome-wide significant QTMs and 21 suggestive hits were identified.
• The top significant QTM (cg24159721) and four others mapped to the microRNA 12136 (MIR12136) gene region.
• Additional significant QTMs were found near the MT-RNR2 (humanin) like 8 (MT-RNRL8), MT-RNR2 (humanin) like 3 (MT-RNRL3), and MT-RNR2 (humanin) like 2 (MT-RNRL2) genes.

Conclusions:

• The identified QTMs provide potential biological insights into OCD pathogenesis.
• Replication in larger samples is needed to validate these findings.
• These QTMs may serve as peripheral epigenetic markers for OCD risk, informing future preventive and therapeutic strategies.