PURPOSE:To investigate mitochondrial DNA(mtDNA) of Leber's hereditary optic neuropathy(LHON). METHODS:Polymerase chain reaction(PCR)method was used to analyse mtDNA of 11 patients in a pedigree with LHON and 4 control subjects from none LHON pedigree. RESULTS:There was a loss of a restriction site for the restriction endonuclease SfaN.Ⅰin Ihe Patients with LHON. In this pedigree,maternal lineage was regarded a carrier of the pathogenic gene. CONCLUSIONS:The patients with Leber's hereditary optic neuropathy have a point mutation in mtDNA,which results in loss ol SfaN I endonuclease restriction site .and this change is one of mechanisms inducing this disaese. （Chin J Ocul Fundus Dis,1997,13: 27-29）
ObjectiveTo observe the clinical features of patients over 30 years old with Leber hereditary optic neuropathy (LHON). MethodsNine male LHON patients (18 eyes) were enrolled in this study. The patients aged from 34 to 56 years old, with an average age of (45.22±6.91) years. The course of the disease ranged from 7 days to 21 months, with a mean course of 5 months. Visual acuity, slit lamp microscope, chromoptometry, direct ophthalmoscope and fundus photography were measured for all patients, visual field examined for 6 patients (11 eyes). Mitochondrial DNA mutation was analyzed. The visual acuity was followed-up for 12 months. ResultsSeven of the 9 patients (77.78%) had family history. Five patients (55.56%) had both eyes involved simultaneously, and 4 patients (44.44%) had the eyes involved at different time. Three patients (33.33%) had sudden visual loss, and 6 patients (66.67%) had gradual visual loss. The visual acuity was light perception in 1 eye (5.55%), finger counting in 3 eyes (16.67%), 0.01-0.1 in 7 eyes (38.89%), 0.12-0.3 in 3 eyes (16.67%), equal or greater than 0.4 in 4 eyes (22.22%). Sixteen eyes (88.88%) had normal light reflex, 1 eye (5.55%) had no light reflex, and 1 eye (5.55%) had relative afferent papillary defect. Eight eyes (44.44%) had normal optic disk, 3 eyes (16.67%) had blurred optic disc border and disc telangiectasia, 7 eyes (38.89%) had pale disc and clear boundary. Among 11 eyes underwent visual field examination, 9 eyes (81.82%) had central or paracentral scotoma and 2 eyes (18.18%) had visual field narrowing. Among 9 patients, there were 7 patients (77.78%) with G11778A mutation, 1 patient (11.11%) with G11696A mutation, and 1 patient (11.11%) with T14484C mutation. In the last follow-up, the visual acuity was light perception in 1 eye (5.55%), finger counting in 4 eyes (22.22%), 0.01-0.1 in 6 eyes (33.33%), 0.12-0.3 in 3 eyes (16.67%), equal or greater than 0.4 in 4 eyes (22.22%).The visual acuity was improved in 9 eyes (50.00%), stable in 7 eyes(38.89%), and decreased in 2 eyes (11.11%). ConclusionLHON patients (older than 30 years) are more common in men, mostly with normal light reflex, central or paracentral scotoma and G11778A mutation.