Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) share certain genetic variants and genes. Additional research focused on these variants can help identify pathophysiological pathways and new treatment goals for these disorders, according to research published in the Journal of Child Psychology and Psychiatry.
A team of researchers performed genomic analyzes, including genomic structural equation modeling and colocalization analysis, of summary data from genome-wide association studies (GWAS) on ASD (n = 46,350) and ADHD (n = 55,374). They attempted to identify single nucleotide polymorphisms (SNPs) that are common to the two diseases, as well as SNPs that are specific to each.
In the colocalization analyzes, the researchers found that 37.5% of the SNPs from ASD were colocalized with SNPs from ADHD (P <1e-6). In addition, approximately 19.6% of the SNPs from ADHD colocalized with SNPs from ASD (P <1e-6).
The study researchers applied FUMA (Functional Mapping and Annotation of GWAS) to the SNPs located between ADHD and ASD, which prioritized 6 genes previously reported in other studies: XRN2, SORCS3, PTBP2, NKX2-4, MANBA, and DPYD. Another 2 new genes, INSM1 and PAX1, were also found.
A bidirectional Mendelian randomization analysis found an association between the risk of ASA and an increased risk of ADHD (β-MR-IVW = 0.51 (0.09); P <0.001; n of SNPs, 15). In the opposite direction, the study researchers found a connection between the ADHD risk and an increased ASD risk (β-MR-IVW = 0.33 (0.05); P <0.001; n of SNPs, 40).
Regarding the study limitations, the researchers noted that the sample overlap in the controls may have led to bias in the results.
Given the results of the study, the researchers suggested that additional “studies of the common and specific genetic factors of neurodevelopmental disorders may help identify pathophysiological pathways and new targets for treatment” in patients with ASD and ADHD.
Peyre H, Schoeler T, Liu C, et al. Combination of multivariate genomic approaches to elucidate the comorbidity between autism spectrum disorder and attention deficit hyperactivity disorder. Published online July 7, 2021. J Child Psychol Psychiatry. doi: 10.1111 / jcpp.13479