MT-ND4 and Leber hereditary optic neuropathy: We have shown here that mutant G11778A ND4 DNA can be introduced into the murine mitochondria of the inner retina, where the expression of the DNA leads to significant mitochondrial perturbations causing loss of visual function, culminating in retinal ganglion cell and optic nerve degeneration that are the hallmarks of human LHON [14,15].