rs11677203 (MIR3681HG): EEG Activity GWAS Variant

Key takeaways

• rs11677203, at the MIR3681HG locus, was examined in a genome-wide scan of resting brain wave (EEG) patterns in 4,026 adolescents and their parents.
• No individual genetic variant in the study, including this one, reached genome-wide statistical significance for any EEG measure.
• Resting EEG activity is strongly heritable (49% to 85%, median 78%), but this likely reflects many small-effect variants acting together rather than a few large ones.
• Much larger sample sizes will probably be required before individual variants like rs11677203 can be reliably detected.

What the research says rs11677203 is located at the MIR3681HG locus and was among the 527,829 single nucleotide polymorphisms (SNPs - positions in the genome where individuals commonly differ by a single DNA letter) examined in a genome-wide association study (GWAS) of resting EEG (electroencephalogram - a measure of brain wave activity recorded from the scalp) in a community sample of 4,026 adolescent twins and their parents. Biometric heritability (the proportion of individual differences in a trait explained by genetic factors) for the EEG parameters measured in that study was estimated at between 0.49 and 0.85, with a median of 0.78, and SNP-based heritability varied across scalp electrode sites. Despite this high heritability, no individual SNP reached genome-wide significance, and the one gene showing a suggestive signal - GABRA2 (encoding a subunit of the receptor for the brain's main inhibitory chemical, GABA) for beta-band power at p < 0.014 - did not survive Bonferroni correction (a standard adjustment for the large number of statistical tests performed).

Reported associations

• Resting EEG delta power (0.1-4 Hz): Several genes, but no individual SNPs including rs11677203, were found to be associated with delta-band brain wave activity at the gene level. No individual effect size for this variant was reported.
• Resting EEG beta power (13-30 Hz): The GABRA2 gene showed a suggestive association with beta-band power at p < 0.014. This finding did not survive correction for multiple comparisons and pertains to the GABRA2 locus, not to rs11677203 directly.

Evidence quality The source study included 4,026 participants (adolescent twins and parents) genotyped at 527,829 SNPs, representing a moderately large family-based GWAS sample for a behavioral trait. Biometric heritability estimates were consistently high across EEG measures (median 0.78), providing strong evidence that EEG activity has a substantial genetic basis as a class of traits. However, no individual variant reached the standard genome-wide significance threshold. The only gene-level finding that approached significance (GABRA2 for beta power, p < 0.014) was explicitly flagged by the authors as not surviving Bonferroni correction. The authors directly conclude that EEG parameters likely follow a polygenic model - meaning that many variants each contribute a very small effect - and that larger sample sizes will be required to detect individual variants reliably. The evidence specific to rs11677203 is therefore preliminary, based on a study in which the variant was examined but not found to be individually significant.

Lifestyle considerations No lifestyle considerations on file for this variant.