Investigating Shared Genetic Basis Across Tourette Syndrome and Comorbid Neurodevelopmental Disorders Along the Impulsivity-Compulsivity Spectrum

Biol Psychiatry. 2021 Sep 1;90(5):317-327. doi: 10.1016/j.biopsych.2020.12.028. Epub 2021 Jan 8.

Abstract

Background: Tourette syndrome (TS) is often found comorbid with other neurodevelopmental disorders across the impulsivity-compulsivity spectrum, with attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) as most prevalent. This points to the possibility of a common etiological thread along an impulsivity-compulsivity continuum.

Methods: Investigating the shared genetic basis across TS, ADHD, ASD, and OCD, we undertook an evaluation of cross-disorder genetic architecture and systematic meta-analysis, integrating summary statistics from the latest genome-wide association studies (93,294 individuals, 6,788,510 markers).

Results: As previously identified, a common unifying factor connects TS, ADHD, and ASD, while TS and OCD show the highest genetic correlation in pairwise testing among these disorders. Thanks to a more homogeneous set of disorders and a targeted approach that is guided by genetic correlations, we were able to identify multiple novel hits and regions that seem to play a pleiotropic role for the specific disorders analyzed here and could not be identified through previous studies. In the TS-ADHD-ASD genome-wide association study single nucleotide polymorphism-based and gene-based meta-analysis, we uncovered 13 genome-wide significant regions that host single nucleotide polymorphisms with a high posterior probability for association with all three studied disorders (m-value > 0.9), 11 of which were not identified in previous cross-disorder analysis. In contrast, we also identified two additional pleiotropic regions in the TS-OCD meta-analysis. Through conditional analysis, we highlighted genes and genetic regions that play a specific role in a TS-ADHD-ASD genetic factor versus TS-OCD. Cross-disorder tissue specificity analysis implicated the hypothalamus-pituitary-adrenal gland axis in TS-ADHD-ASD.

Conclusions: Our work underlines the value of redefining the framework for research across traditional diagnostic categories.

Keywords: ADHD; ASD; Cross-disorder genetic analysis; GWAS meta-analysis; OCD; Tourette syndrome.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Attention Deficit Disorder with Hyperactivity* / epidemiology
  • Attention Deficit Disorder with Hyperactivity* / genetics
  • Autism Spectrum Disorder* / genetics
  • Comorbidity
  • Genome-Wide Association Study
  • Humans
  • Impulsive Behavior
  • Obsessive-Compulsive Disorder* / epidemiology
  • Obsessive-Compulsive Disorder* / genetics
  • Tourette Syndrome* / epidemiology
  • Tourette Syndrome* / genetics