RESUMO
INTRODUCTION: Leber's hereditary optic neuropathy (LHON) is a mitochondrial disorder, confirmed at a molecular level 10 years ago. This had permitted better understanding of the condition. Since 1998, the Instituto de Neurología y Neurocirugía has used these techniques for the study of mutations which are considered to be the origin of the disorder. PATIENTS AND METHODS: We describe the characteristics of 14 cases from 10 families with LHON and the molecular confirmation found between 1994 and 1998 in the Instituto de Neurología Neurocirugía de Cuba. We also review the few cases seen in the previous 18 years. These were from only two families. They were diagnosed on clinical grounds and in view of maternal inheritance. RESULTS AND CONCLUSIONS: In 80% of the families in which the presence of primary mutations was investigated there was A117789, and in 20% A3460G. The average age of appearance was 28 years. The ages of onset were within the limits of 11 years and 48 years. There were 43% women. Two cases were considered to be sporadic. The clinical features corresponded to those described in such cases, with severe visual defects, central scotomas, very reduced colour vision and severely altered visual evoked potentials, with normal diffuse light and pattern electroretinograms. An improvement in visual acuity of 0.2 was seen in two cases. Microangiopathy, described as characteristic of the early stages of this disorder was detected in five cases, in at least one eye. The others had different degrees of optic atrophy. Two generations of one complete family, all with mutation 3460, were studied. In several families with this mutation alterations were found in the colour vision test of Farnsworth Munsell Hue 100 and also microangiospathy of the retina.