Shared genetic architecture between autism spectrum disorder, loneliness, and social isolation reveals novel genetic loci.

Researchers studied the genes linked to autism, loneliness, and social isolation using data from hundreds of thousands of people. They found that autism and loneliness share many genetic factors, while autism and social isolation share genes in specific brain regions. The study discovered 12 new genetic locations linked to autism that involve brain chemicals like GABA and glutamate, stress hormones, and immune system function. This suggests there are biological reasons why autistic people often experience loneliness and social isolation.

This genome-wide association study analyzed genetic data from large cohorts to examine shared genetic architecture between autism spectrum disorder (ASD), loneliness, and social isolation. The study found a moderate positive genetic correlation between ASD and loneliness (rg = 0.26), while ASD and social isolation showed no global correlation but significant local genetic sharing. Advanced statistical methods identified 17 specific genetic loci shared between ASD and these social traits, with 12 being novel ASD-related loci. These shared genetic variants implicate biological pathways involving GABA, glutamate, calcium signaling, stress hormones, glucose transport, TAU-accumulation, and immune function, suggesting common biological mechanisms underlying social difficulties in autism.

Findings suggest loneliness in autism has genetic underpinnings, supporting early screening and intervention. The identified pathways (GABA, glutamate, immune function) may inform targeted therapeutic approaches. Understanding genetic predisposition to social difficulties could guide personalized support strategies and help clinicians better predict and address social challenges in autistic individuals.

The study relies on genome-wide association data which cannot establish causation. The analysis is limited to genetic correlations and does not account for environmental factors. The clinical significance of identified genetic variants requires further validation through functional studies.

Deficits in social communication and social interaction are core features of autism spectrum disorder (ASD), and studies suggest that loneliness and social isolation are common. ASD has a strong genetic basis, but the genetic architecture and overlap with social phenotypes are not clear. We analyzed summary statistics from genome-wide association studies on ASD (46 350), loneliness (452 302), and social isolation (288 950), using linkage disequilibrium score regression, local analysis of covariant annotation (LAVA), bivariate causal mixture model (MiXeR), and the conditional/conjunctional false discovery rate (cond/conjFDR). For ASD and social isolation, we found nonsignificant global genetic correlation ( rg = 0.02, P  = 0.8), but LAVA identified 72 genomic regions with bidirectional correlations, and MiXeR estimated that 8.7 k of 13.1 k variants (81%) were shared, of which 53% had concordant effect directions.

For ASD and loneliness, we found a positive genetic correlation ( rg = 0.26, P  = 2e-10), LAVA identified 80 genomic regions with bidirectional genetic correlations, and MiXeR suggested that at least 3.8 k variants were shared. We identified nine specific shared genetic loci between ASD and loneliness and eight between ASD and social isolation (conjFDR < 0.05). Of these, 12 loci were novel for ASD. Genes mapped to these loci are involved in γ-aminobutyric acid (GABA), glutamate, calcium, and stress hormone signaling, cerebral glucose transport, TAU-accumulation, and immune function.

We found extensive overlap in genetic architecture between ASD, loneliness, and social isolation, with bidirectional effects. By leveraging data for ASD and social traits, we identified 12 novel ASD related genetic loci implicating several genes, thereby elucidating potential pathways underlying their shared genetic architecture.