NEUROMYODredger: Whole Exome Sequencing for the Diagnosis of Neurodevelopmental and Neuromuscular Disorders in Seven Countries.

Although substantial advancements have been made in genetic testing, several barriers continue to limit patient access, leading to delays in diagnosis, effective treatments, and preventative measures. The NEUROMYODredger-3billion Megaproject End the Diagnostic Odyssey grant offered free whole exome sequencing (WES) to 245 patients with undiagnosed neurodevelopmental or neuromuscular disorders in seven countries: Algeria, Chile, Egypt, France, Mexico, Peru, and Romania. We found pathogenic variants in 79 patients (diagnostic yield 32.24%)-36 neurodevelopmental (43.90%) and 43 neuromuscular (26.38%). Fifty patients harboured variants of uncertain significance (VUS, 20.40%)-14 neurodevelopmental (17.07%) and 36 neuromuscular (22.08%), and 116 patients had negative results (47.34%). NEUROMYODredger helped end the diagnostic odyssey in around 30% of patients, while ongoing functional studies and reanalysis strategies are used in order to reach more diagnoses. In conclusion, a singleton WES approach is valuable in determining the genetic diagnosis of neurodevelopmental and neuromuscular diseases, especially in low and middle-income countries.