Shared Genetics of Asthma and Mental Health Disorders: A Large-Scale Genome-Wide Cross-Trait Analysis

Epidemiological studies demonstrate an association between asthma and mental health disorders, although little is known about the shared genetics and causality of this association. Thus, we aim to investigate shared genetic and the causal link between asthma and mental health disorders. We conducted a large-scale genome-wide cross-trait association study to investigate genetic overlap between asthma from UK Biobank and 8 mental health disorders from Psychiatric Genomics Consortium, including: attention deficit hyperactivity disorder (ADHD), anxiety disorder (ANX), autism spectrum disorder, bipolar disorder, eating disorder, major depressive disorder (MDD), posttraumatic stress disorder, and schizophrenia, with a sample size of 7556 to 446 032. In the single trait genome-wide association analysis, we replicated 130 and discovered 31 novel independent loci that are associated with asthma. We identified that ADHD, ANX and MDD have strong genetic correlation with asthma at the genome-wide level. Cross-trait meta-analysis identified 7 loci jointly associated with asthma and ADHD, 1 loci with asthma and ANX and 10 loci with asthma and MDD. Functional analysis revealed that the identified variants regulated gene expression in major tissues belonging to exocrine/endocrine, digestive, respiratory and hemic/immune system. Mendelian randomisation analyses suggested that ADHD and MDD (including 6.7% samples overlap with asthma) might increase the risk of asthma. This large-scale genome-wide cross-trait analysis identified shared genetics and potential causal links between asthma and three mental health disorders (ADHD, ANX, and MDD). Such shared genetics implicate potential new biological functions that are in common among them.