Leber’s Hereditary Optic Neuropathy (LHON)

Summary

Background.
Leber’s hereditary neuropathy of the optic nerve (LHON) is manifested by bilateral affection of theeyes with acute or subacute loss of vision. The disease is caused by point mutations in the mitochondrial DNA(mtDNA) and is one of the most frequent mitochondrial diseases in the population. In patients with LHON 18different point mutations in the mtDNA were described which correlate partly with the rate of progression of thedisease and the severity and prognosis of the final affection of vision.Methods and Results. The submitted paper deals with the results of molecular genetic examinations in threefamilies with clinical manifestations of LHON. In three patients in the first family a homoplasmic mutation ofmtDNA G3460A was found. In the second family in a young man with severely impaired vision a heteroplasmicmutation G3460A was found associated with a higher ratio of mutated mtDNA molecules than in his mother whois clinically healthy. In the third family the presence of homoplasmic mutation of mtDNA in position G11778A wasdetected.Conclusions. The diagnosis of LHON and genetic counselling in affected families should be based on closecollaboration of ophthalmological and genetic departments with specialized laboratories engaged in molecularbiological diagnosis of mitochondrial diseases.

Key words:
blindness, LHON, mtDNA, mutation G3460A, mutation G11778A, heteroplasmia.