In Silico Characterization of RNASEH2A Pathogenic Variants and Identification of Novel Splice Site Donor Variant c.549+1G>T in Indian Population

Background Aicardi-Goutieres syndrome (AGS) is a genetic disorder that has variable manifestations including neurological, immunological, and sometimes other system involvement in various combinations. Considering the high genetic and clinical diversity of AGS and the importance of RNASEH2 complex in the biological system, it is important to take a systematic approach to delineate the genetic diagnosis and impact of missense mutations. Methods Clinical targeted gene sequencing followed by Sanger validation was performed in an individual with the clinical features of AGS. Protein modeling studies of all the reported RNASEH2A missense variants till date were performed using freely available web servers BioGrid, ShinyGO. Protein structures were visualized using Pymol. Results and discussion We identified a novel homozygous splice site donor variant c.549+1G>T in RNASEH2A. Furthermore protein-interactome studies identifiedpotential genetic interactors that include RNASEH2A, RNASEH2B, TYMS, RNASEH2C, RPA1, ORC3, ORC2, CDC6, PCNA, LIG1, PRIM1, RFC2, DUT, GINS1, MCM7, FEN1, MCM4, GINS2, CDK4, and MCM5. Identified genes were mapped to specific pathways using SHINY GO. DNA replication and cell cycle, centrosome cycle, post-replication repair, nucleic acid and metabolic process, cellular response to stress, DNA metabolic process, nucleic acid phosphodiester bond hydrolysis, RNA phosphodiester bond hydrolysis, and DNA biosynthetic process were identified as the linked pathways with the prioritized genes. Conclusion In conclusion, a sophisticated genotype and phenotype correlation followed by linking the genes to the key biological pathways opens new avenues to understand disease pathology and plan for therapeutic interventions.