Objectives To observe the clinical characteristics of Leber congenital amaurosis (LCA) and analyze the features to differentiate LCA from other similar disorders.Methods Prospective study of 15 LCA patients which include 10 males and 5 females, aged from 2 to 31 years with the mean age 13.6 years. Medical history, family history, perinatal conditions, as well as complete ocular evaluations were well documented. Among the subjects, 12 patients underwent optometry check, 10 patients underwent ERG and 8 patients had OCT testing. Results All of the patients had nystagmus and sluggish pupillary reflex. The visual acuity distributed from light perception to 0.1. Fivepatients (33.3%) were presented with photophobia, while 7 patients (46.7%) had nyctalopia. Among 12 cases underwent refraction examination, 6 patients (50%) had spherical equivalent of ge;+5D；1 patient（8.3%）had spherical equivalent of ge;+5D; 2 patients (16.7%) had bilateral mild to moderate hyperopia；1 patient (8.3%) had one emmertropic eye and one mild myopic eye; 2 patients (16.7%) had moderate to high myopia. Eight patients (53.3%) had enophthalmus,4 patients (26.7%) had oculodigital sign. All of the 10 patients underwent ERG showed extinguished waveform. Under OCT assesement, 7 patients had decreased fovea thickness; 1 patient had increased fovea thickness, complicated by epiretinal membrane; mild abnormality of microstructure of the retina with diminished and disrupted IS/OS hyperreflectivity were found in 2 cases；while more pronounced disarrangement of the retinal layers were found in 6 cases，inner layers were better reserved in all patients.Conclusions Severe visual impairment or blindness, nystagmus, pupillary reflex, extinguished ERG and hyperopia are main clinical characteristics of LCA.
Optic atrophy,hereditary／diagnosis; Polymerase chain reaction; DNA,mitochondrial; Point mutation; Sequence analysis
Objective To find the new mutations of Leber's hereditary optic neuropathy (LHON). Methods Two LHON families were enrolled in this study. The probands and all maternal members in this two families were underwent ophthalmologic examinations. The ages of probands were seven and 14 years old respectively. A total of 358 healthy adults were enrolled in this study as control group. The genomic DNA from whole blood of participants were extracted. The entire mitochondrial genome of probands were PCR amplified and sequenced in 24 overlapping fragments using primers as designed. At the same time, the mtDNA of maternal relatives and 358 controls were also detected. Fourteen primate species were selected from GenBank to analyzed the phylogenetics of mitochondrial sequence. Results There was no ND4 G11778A, ND1 G3460A, ND6 T14484C mutational site in all maternal members. Molecular analysis of mtDNA in this two families identified the homoplasmic tRNAGluA14683G mutation and distinct set of variants belonging to the Asian haplogroup F1a1 and G2. The site was at theTpsi;C stem oftRNAGlu and extremely conserved among 14 primate species. It was anticipated that the A14683G increased the highly conserved C-G basepairing. Furthermore, the A14683G was absence in control group. Conclusion The tRNAGluA14683G mutation is likely a new mutation associated with LHON.