rs12446262 (ZNF423): Nightmare Frequency Genetics

Key takeaways

• Nightmares share strong genetic overlap with anxiety, depression, PTSD, and neuroticism.
• Genetic evidence suggests insomnia causally increases nightmare frequency rather than just co-occurring with it.
• Nightmares have roughly 5% heritability, meaning genetics plays a real but modest role.
• This variant was studied in a genome-wide analysis of nightmare frequency in 45,255 individuals.
• No single variant reached genome-wide significance in the nightmare GWAS, so evidence for this specific locus is preliminary.

What the research says A genome-wide association study (GWAS, a statistical scan that tests hundreds of thousands of genetic positions simultaneously) of nightmare frequency in 45,255 individuals found no genome-wide significant risk variants, with heritability estimated at approximately 5% (meaning roughly 5% of variation in nightmare frequency across individuals can be attributed to common genetic differences). Genetic correlation analysis (a method quantifying how much the genetic influences on two traits overlap) found strong correlations between nightmare frequency and anxiety (rg = 0.671, p = 7.507e-06), depressive disorders (rg = 0.562, p = 1.282e-07), post-traumatic stress disorder (PTSD, rg = 0.408, p = 0.0152), and neuroticism (a personality trait reflecting emotional instability, rg = 0.667, p = 4.516e-07). Mendelian randomization (a technique that uses genetic variants as statistical instruments to test causal relationships) suggested that insomnia increases liability to frequent nightmares (beta = 0.027, p = 0.0002), rather than insomnia and nightmares merely co-occurring without a directional causal link.

Reported associations

• Nightmare frequency: A GWAS of 45,255 individuals found no genome-wide significant variants at this locus; heritability was estimated at approximately 5%.
• Anxiety (genetic correlation): Strong shared genetic architecture between nightmare frequency and anxiety disorder traits (rg = 0.671, p = 7.507e-06).
• Depressive disorders (genetic correlation): Genetic overlap between nightmare frequency and depressive disorders (rg = 0.562, p = 1.282e-07).
• Post-traumatic stress disorder (genetic correlation): Partial shared genetic architecture between nightmare frequency and PTSD (rg = 0.408, p = 0.0152).
• Neuroticism (genetic correlation): Strong genetic overlap between nightmare frequency and the personality trait neuroticism (rg = 0.667, p = 4.516e-07).
• Insomnia (causal pathway): Mendelian randomization analysis suggested that insomnia causally increases nightmare frequency (beta = 0.027, p = 0.0002), not merely co-occurring with it.

Evidence quality The nightmare GWAS included 45,255 individuals, a substantial sample; however, by current GWAS standards, traits with low heritability often require samples exceeding 100,000 participants to reliably detect individual variants. No individual genome-wide significant risk variants were found (conventional threshold: p < 5 x 10-8), consistent with the low heritability estimate of 5%. Genetic correlation estimates describe shared genetic architecture across whole genomes and are not specific to any single variant or locus. The Mendelian randomization estimate for insomnia increasing nightmare frequency is statistically significant but small in effect size (beta = 0.027). The source study text does not specify association statistics at the ZNF423 (Zinc Finger Protein 423, a transcription factor gene) locus, and evidence linking rs12446262 to any specific trait should be considered preliminary.

Lifestyle considerations No lifestyle considerations on file for this variant.