Common genetic variants influence human subcortical brain structures

Nature

(2015)

doi:10.1038/nature14101

Received: 17 April 2014
Accepted: 19 November 2014
Published online: 21 January 2015

The highly complex structure of the human brain is strongly shaped by genetic influences¹. Subcortical brain regions form circuits with cortical areas to coordinate movement², learning, memory³ and motivation⁴, and altered circuits can lead to abnormal behaviour and disease². To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume derived from magnetic resonance images of 30,717 individuals from 50 cohorts. We identify five novel genetic variants influencing the volumes of the putamen and caudate nucleus. We also find stronger evidence for three loci with previously established influences on hippocampal volume⁵ and intracranial volume⁶. These variants show specific volumetric effects on brain structures rather than global effects across structures. The strongest effects were found for the putamen, where a novel intergenic locus with replicable influence on volume (rs945270; P = 1.08 × 10⁻³³; 0.52% variance explained) showed evidence of altering the expression of the KTN1 gene in both brain and blood tissue. Variants influencing putamen volume clustered near developmental genes that regulate apoptosis, axon guidance and vesicle transport. Identification of these genetic variants provides insight into the causes of variability in human brain development, and may help to determine mechanisms of neuropsychiatric dysfunction.