Shared genetic architecture between schizophrenia and subcortical brain susceptibility phenotypes.

Developmental and cellular vulnerabilities underlie genetic architecture of schizophrenia.

Genetically informed dissection of multimodal brain aging and ten major psychiatric disorders.

Shared genetic architecture between brain iron deposition and Alzheimer's disease

Brain iron accumulation is well established in Alzheimer's disease (AD), but whether the two share a genetic basis remains unclear. Here, we performed genome-wide association analyses of brain iron across six iron-rich brain regions, quantified via quantitative susceptibility mapping (QSM) in 38,142 UK Biobank participants. Genetic pleiotropic overlap, genetic correlation and genomic structural equation modelling were used to identify shared genetic architecture between brain iron and risk of AD, and bidirectional Mendelian randomisation was used to test for causal relationships. We identified 116 independent genome-wide significant loci associated with brain iron (r2<0.1; p <5 x 10-8) and validated these signals in an independent cohort using polygenic scores, which explained between 8.9% and 25.4% of variance in regional iron. Genetic pleiotropy and correlation analyses revealed that brain iron and AD share a polygenic basis extending well beyond the canonical APOE locus. This shared liability is specific to basal ganglia structures relevant to cognition, specifically, iron deposition across the caudate nucleus, putamen, and globus pallidus loaded onto a single latent factor that correlated significantly with AD (rg = 0.13, P = 0.019). Multivariate genome-wide association analysis of the shared liability factor between AD and brain iron revealed 27 independent genome-wide significant loci implicating genes that modulate neuroimmune function. Mendelian randomisation provided no evidence of a causal effect in either direction. In summary, we identified region-specific shared genetic liability between brain iron and AD, and a putative neuroimmune mechanism underlying it.

Genome-wide analysis of subcortical aging identifies a spatially structured pattern of genetic associations.

Local brain age (LBA) is a spatially resolved biomarker of brain aging that captures regional deviations from chronological age, yet its genetic architecture in the subcortex remains unexplored. Here, we present the first genome-wide association study (GWAS) of subcortical LBA, estimated using a deep neural network applied to T1-weighted MRI scans from 41,957 cognitively normal participants in the UK Biobank. We computed LBA across 14 subcortical structures and identified 14 significant single-nucleotide polymorphisms (SNPs) across nine independent loci. These variants map to genes involved in cellular homeostasis, gene regulation, and synaptic and developmental signaling. A prominent signal emerged at the 17q21.31 haplotype, encompassing MAPT-related regulatory architecture, with significant associations across all subcortical regions. Across loci, we observed a recurring spatial pattern in which effect sizes are relatively larger in metabolically central structures such as the pallidum and thalamus compared to limbic regions. Together, these findings support a spatially structured pattern of genetic associations in subcortical brain aging. This work supports subcortical LBA as a genetically informed phenotype and provides a framework for linking common genetic variation to region-specific vulnerability and resilience in neurodegenerative disease.

Mapping genetic convergence across brain structure, mental health, and cardiometabolic disease

It is found that schizophrenia and ADHD show distinct genetic patterns: schizophrenia shares more genetic factors with brain structure and diabetes, while ADHD is more strongly linked to metabolic pathways.

Shared genetic architecture between major depression and intrinsic brain functional connectome organization.

BACKGROUND Major depression (MD) is increasingly understood as a disorder characterized by widespread abnormalities in intrinsic brain functional network organization. Although both MD and brain functional connectome architecture are highly heritable, the genetic architecture underlying their relationship remains poorly characterized. METHODS We integrated genome-wide association studies of MD with 191 ICA-based resting-state functional connectome traits to investigate their shared genetic architecture. These traits captured intrinsic connectome organization across amplitude, functional connectivity, and global connectivity domains. Cross-trait genetic analyses were used to assess pleiotropic overlap between traits. Locus-level and gene-based analyses integrating multi-omics evidence were performed to characterize the biological relevance of shared genetic signals. RESULTS We identified significant genetic overlap between MD and 148 of 191 brain functional connectome traits. Cross-trait analyses revealed widespread shared genetic signals organized into 627 genomic loci across amplitude, functional connectivity, and global connectivity measures. Among these, 193 loci showed evidence consistent with shared causal variants based on colocalization analyses. Gene-level integration mapped these loci to 1459 protein-coding genes (390 unique genes). Multi-layer prioritization identified 17 high-confidence genes supported by convergent genomic, transcriptomic, and proteomic evidence, with enrichment in neurodevelopmental and lipid-related metabolism pathways. CONCLUSIONS This study provides a multi-scale characterization of the shared genetic architecture between MD and intrinsic brain functional connectome organization, revealing that shared genetic signals between MD and brain functional systems are distributed across multiple functional levels and converge at the molecular level.