The First Insight into the Hereditary Fusion Gene Landscape of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive nervous system disease that causes loss of muscle control. Over 30 mutated genes are associated with ASL. However, 90-95% of ASL cases have been found without a family history. Here, we have analyzed RNA-Seq data of NYGC ALS Consortium and identified fusion transcripts from ASL patients and non-neurologic controls (NNC). In this study, we combined previously-curated 1180 monozygotic (MZ) hereditary fusion genes (HFGs), and 204 HFGs discovered from NNC to analyze ASL fusion transcripts and identified 348 HFGs. Comparative analysis between ASL and GTEx shows that 139 HFGs are associated with ASL and ranged from 10.4% to 98.7% of 77 ASL patients. The most recurrent HFG is ZNF528-ZNF880, detected in 98.7% of 77 ASL patients and 4.5% of 133 GTEx brain cortexes. Alignments of HFG transcripts from ASL with fusion transcripts from mesial temporal lobe epilepsy (MTLE) and Alzheimers disease (AD) showed that 43.9% and 11.6% of the ASL HFGs were present in MTLE and AD, respectively. The most recurrent and common HFG among ASL, MTLE, and AD was ADAMTSL3-SH3GL3, which behaves like ubiquitously-expressed SH3GL3-ADAMTSL3 epigenetic fusion gene (EFG) and shows that ADAMTSL3-SH3GL3 is a potential dormant or differentially-expressed HFG (dHFG), suggesting that they have common pathophysiological mechanisms. These HFGs associated with ASL have shown that HFGs are the missing genetic heritability and provide novel therapeutic targets for more efficient therapeutic drugs and methods to treat and cure many neurological diseases.