Rapid exome sequencing as the first-tier investigation for diagnosis of acutely and severely ill children and adults in Thailand.

The use of rapid DNA sequencing technology in severely ill children in developed countries can accurately identify diagnoses and positively impact patient outcomes. This study sought to evaluate the outcome of Thai children and adults with unknown etiologies of critical illnesses with the deployment of rapid whole exome sequencing (rWES) in Thailand. We recruited 54 unrelated patients from 11 hospitals throughout Thailand. The median age was 3 months (range, 2 days-55 years) including 47 children and 7 adults with 52% males. The median time from obtaining blood samples to issuing the rWES report was 12 days (range, 5-27 days). A molecular diagnosis was established in 25 patients (46%), resulting in a change in clinical management for 24 patients (44%) resulting in improved clinical outcomes in 16 patients (30%). Four out of seven adult patients (57%) received the molecular diagnosis which led to a change in management. The 25 diagnoses comprised 23 different diseases. Of the 34 identified variants, 15 had never been previously reported. This study suggests that use of rWES as a first-tier investigation tool can provide tremendous benefits in critically ill patients with unknown etiology across age groups in Thailand.