Sema4 announced the results of a new study on mitochondrial diseases in newborns. The findings support the addition of mitochondrial DNA (mtDNA) testing to rapid exome sequencing, showing it can lead to earlier diagnoses and more immediate potential changes in clinical management. The research evaluates the incidence of mitochondrial disease caused by both nuclear DNA (nDNA) and mtDNA in 966 infants in the NICU who received both rapid exome sequencing and mtDNA sequencing and deletion testing concurrently.

Mitochondrial diseases are chronic, genetic disorders that occur when mitochondria fail to produce enough energy for the body to function properly. These can affect multiple organ systems at different ages. Mitochondrial diseases are individually rare but, collectively, as this study shows, this group of disorders is not uncommon in clinical settings.

In the study conducted by Sema4|GeneDx, nearly 10% of infants referred for exome sequencing plus mtDNA testing were diagnosed with a mitochondrial disorder, accounting for 29% of the overall diagnostic cases. 1.3% of diagnoses were made via mtDNA testing. The findings are especially important for infants presenting with the most common symptoms, including lactic acidosis, seizures, and hypotonia.