AARS1 and inborn mitochondrial metabolism disorder: GDF15 was not a protein included in the targeted proteomic screening but is established already as a biomarker for mitochondrial disease, recently indicated to be elevated in Gars mice as well as in patients carrying pathogenic variants in GARS, AARS and PMP22d.44 Therefore, we investigated whether it may have biomarker characteristics in our CMT cohort.