Diagnostic Utility of RNA Sequencing for Rare Disease Variants

This technical report outlines the diagnostic utility of RNA sequencing (RNAseq) in the reclassification of variants of uncertain significance (VUS) identified through genome sequencing (GS) and exome sequencing (ES). The study presents a retrospective review of GS/ES and RNAseq results, focusing on cases where RNAseq was utilized to clarify the significance of variants associated with patient phenotypes. The report details the inclusion criteria for the study, which involved consecutive GS/ES cases with clinical RNAseq opt-in. Among the analyzed cases, 139 had RNAseq eligible variants, including 129 VUS and 17 likely pathogenic variants. The findings indicate that RNAseq can provide functional evidence for more accurate variant classification, enhancing diagnostic yield. The report concludes that RNAseq's ability to identify noncoding variants supports its inclusion in clinical GS and ES workflows, thereby improving the interpretation of genetic variants in rare diseases.