Genome-wide association study identifies 48 common genetic variants associated with handedness

Area of Science:

• Neurogenetics
• Human Genetics
• Behavioral Genetics

Background:

• Handedness is linked to language processing and over-represented in neurodevelopmental disorders.
• Understanding the genetic basis of handedness is crucial for neuroscience and psychiatry.

Purpose of the Study:

• To conduct a genome-wide association meta-analysis to identify genetic loci associated with handedness.
• To explore the genetic underpinnings of left-handedness and ambidexterity.
• To investigate the genetic relationship between handedness and neuropsychiatric traits.

Main Methods:

• Genome-wide association meta-analysis of handedness using large datasets (UK Biobank, 23andMe, International Handedness Consortium).
• Sample size of 1,766,671 individuals.
• Tissue-enrichment analysis and genetic correlation analyses.

Main Results:

• Identified 41 loci associated with left-handedness and 7 loci associated with ambidexterity.
• Central nervous system (CNS) implicated in the etiology of handedness.
• Suggestive positive genetic correlations found between left-handedness and schizophrenia and bipolar disorder.
• Low genetic correlation between left-handedness and ambidexterity suggests distinct genetic mechanisms.

Conclusions:

• Handedness is a highly polygenic trait.
• Genetic variants predisposing to left-handedness may contribute to the association with certain psychiatric disorders.
• Distinct genetic factors likely influence left-handedness and ambidexterity.