NEFH and Leber hereditary optic neuropathy: Since heavily phosphorylated axonal form of the neurofilament heavy chain (pNF-H) has been shown to be a prospective marker of neurodegeneration [25], we evaluated serum pNF-H levels in a large Brazilian pedigree [26,27] to determine the profile of axonal and RGC loss in LHON patients and asymptomatic carriers of mutated G11778A mtDNA.