Rapid Targeted Sequencing Using Dried Blood Spot Samples for Patients With Suspected Actionable Genetic Diseases

Abstract

Background: New genome sequencing technologies with enhanced diagnostic efficiency have emerged. Rapid and timely diagnosis of treatable rare genetic diseases can alter their medical management and clinical course. However, multiple factors, including ethi-cal issues, must be considered. We designed a targeted sequencing platform to avoid eth-ical issues and reduce the turnaround time.Methods: We designed an automated sequencing platform using dried blood spot sam-ples and a NEOseq_ACTION panel comprising 254 genes associated with Mendelian dis-eases having curable or manageable treatment options. Retrospective validation was per-formed using data from 24 genetically and biochemically confirmed patients. Prospective validation was performed using data from 111 patients with suspected actionable genetic diseases.Results: In prospective clinical validation, 13.5% patients presented with medically ac-tionable diseases, including short-or medium-chain acyl-CoA dehydrogenase deficiencies (N= 6), hyperphenylalaninemia (N=2), mucopolysaccharidosis type IVA (N= 1), alpha thalassemia (N= 1), 3-methylcrotonyl-CoA carboxylase 2 deficiency (N= 1), propionic aci-demia (N= 1), glycogen storage disease, type IX(a) (N=1), congenital myasthenic syn-drome (N= 1), and citrullinemia, type II (N= 1). Using the automated analytic pipeline, the turnaround time from blood collection to result reporting was <4 days.Conclusions: This pilot study evaluated the possibility of rapid and timely diagnosis of treat-able rare genetic diseases using a panel designed by a multidisciplinary team. The auto-mated analytic pipeline maximized the clinical utility of rapid targeted sequencing for med-ically actionable genes, providing a strategy for appropriate and timely treatment of rare genetic diseases.