Integrated multi-omics for rapid rare disease diagnosis on a national scale

The Australian Acute Care Genomics program provides ultra-rapid diagnostic testing to critically ill infants and children with suspected genetic conditions. Over two years, we performed whole genome sequencing (WGS) in 290 families, with average time to result of 2.9 days, and diagnostic yield of 47%. We performed additional bioinformatic analyses and transcriptome sequencing in all patients who remained undiagnosed. Long-read sequencing and functional assays, ranging from clinically accredited enzyme analysis to bespoke quantitative proteomics, were deployed in selected cases. This resulted in an additional 19 diagnoses, and an overall diagnostic yield of 54%. Diagnostic variants ranged from structural chromosomal abnormalities through to an intronic retrotransposon, disrupting splicing. Critical care management changed in 120 diagnosed patients (77%). Results informed precision treatments; surgical and transplant decisions; and palliation in 94 (60%). We propose that integration of multi-omic approaches into mainstream diagnostic practice is necessary to realise the full potential of genomic testing.