Overlapping genetic susceptibility of seven autoimmune diseases:SPU tests based on genome-wide association summary statistics

Autoimmune diseases are a heterogeneous group of diseases with an unclear aetiology. Genome-wide association studies (GWAS) and meta-analysis are inefficient in identifying shared variants. This study aims to identify shared genetic susceptibility for seven autoimmune diseases using sum of powered score (SPU) tests. GWAS summary statistics datasets of seven autoimmune diseases were downloaded from Open Targets Genetics, Dryad and In-ternational Multiple Sclerosis Genetics Consortium (IMSGC). The MTaSPUs was applied to confirm common single-nucleotide polymorphisms (SNP), MTaSPUsSet and aSPUs were performed to identify potential shared genes, and MTaSPUsPath was conducted to explore biological functions based on Kyoto encyclopedia of genes and genomes (KEGG) biological pathways. The MTaSPUs test found 104 pleiotropic SNPs (P < 1.19 x 10-6) in our study. The 38 of these SNPs were associated with at least one trait in the original GWAS study. A total of 56 genes associated with at least one trait (P < 4.98 x 10-6) were recognized by aSPUs test. The 45 potential pleiotropic genes (P < 4.98 x 10-6) were significant in MTaSPUsSet test. By aggregating results of aSPUs test and MTaSPUsSet test, we ascertained 38 pleiotropic genes. The 10 of these 38 pleiotropic genes have been reported in previous studies, while the remaining 28 genes were newly discovered. These 38 genes were matched in 14 significant KEGG pathways. We found new variants linked with complicated illnesses derived from several GWAS datasets using the SPU testing technique. The discovery of pleiotropic genes and shared pathways may aid in the development of common treatment approaches for autoimmune disorders.