MT-ND4 and mitochondrial disease: The A3243G, T8821C and C11994T mutations in the mt-TL1, ATPase 6 and ND4 genes, respectively, are known mutations in the mtDNA which have been associated with mitochondrial diseases and asthenozoospermia [7,26]; these 3 point mutations were not detected in the mtDNA of the study participants in this study.