Fig. 1

Study design and cohort characteristics. a ALS samples were distinguished based on pedigrees that allowed maternal or non-maternal inheritance and compared to controls. b Samples of cohort 1 consist of whole blood, whereas cohort 2 comprises freshly isolated platelets (PLT) and white blood cells (WBC). From each sample, mtDNA sequences and mitochondrial mass were examined using Affymetrix MitoChip v2.0 or mtDNA copy number and the citrate synthase activity determination, respectively. (Created with BioRender.com) c Mean age and gender of the study cohorts are listed, including the number of individuals within each group. d Haplogroup analysis was performed for all maternally (mat) and non-maternally (non-mat) associated ALS patients and the control group using PLT or whole blood data (Fisher’s exact test with simulated p-value, p = 0.1114)