Another patient with the Arg383Cys mutation (compound heterozygous His123Pro from the mother; Arg383Cys from the father) is a 17‐year‐old girl (Patient 3F) who displayed developmental delay, encephalopathy, elevated CSF lactate and abnormal respiratory enzymes, consistent with reported clinical features for FARS2 defects. Here, FARS2 is linked to Encephalopathy.