Hereditary optical neuropathy Leber's
Hereditary optical neuropathy Leber’s (LHON) or optical atrophy Leber mitohondrialno nasledstvenny (mother to all posterity) a degeneration setchatochnyh ganglion cells (RGCs) and their axons which leads to acute or subacute losses of the central vision; it damages preobladajushche young adult men. However, LHON only it is transmitted through mother as it occurs first of all because of mutations in mitohondrialnom (not kernel) a gene, and only egg imports a mitochondrion to an embryos. LHON usually occurs because of one of three pathogenic mitohondrialnyh DNA (mtDNA) punctual mutations. These mutations damage standings of a nucleotide 11778, 3460 and 14484, accordingly in ND4, ND1 and genes of subgroup ND6 of a complex of I oxidizing chains fosforiljatsii in a mitochondrion. Men cannot transmit illness to their posterity.
Symptoms and symptoms
Clinically, there is an acute beginning visual losses, at first in one eye, and then some weeks later in other. It ultimately develops to very serious optical atrophy and permanent reduction of visual acuteness. In the acute stage lasting of some weeks, the defective eye shows hydropic occurrence of a stratum of a fiber of a nerve especially in arched ligaments both enlarged or telangectatic and twisting peripapilljarnyj a vessel (mikroangiopatija). These main signs are noted on examination of a bottom, just before or the subsequent to the beginning visual losses. Examination shows the reduced visual acuteness, losses of color vision and cecocentral scotomas on visual field examination.
The diagnosis and guidance
The diagnosis is extremely difficult and usually demands a neuro-ophthalmologic estimate and-or testing of blood for DNA examination (which it is accessible only in several laboratories). Hence the incidence possibly is much more than appreciating. The forecast - almost always the forecast of long-term very serious visual losses. There is no accepted treatment for this illness.
Hereditary optical neuropathy Leber’s is sometimes confused to congenital amaurosis Leber's which is the various illness also at first featured Teodorom Leber in 19th century.
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