Mount Elbrus 100 people to be attempting the summit via this route each day. Winter ascents are rare, and are usually undertaken only by very experienced climbers. Elbrus is notorious for its brutal winter weather, and summit attempts are few and far between. The climb is not technically difficult, but it is physically arduous because of the elevations and the frequent strong winds. The average annual death toll on Elbrus is 15–30, primarily due to "many unorganized and poorly equipped" attempts to summit the mountain. Since 1986, Elbrus has been incorporated into Prielbrusye National Park, one of the Protected areas of Russia.
MT-ND3 mtDNA-associated Leigh syndrome, as are variants of MT-ATP6, MT-TL1, MT-TK, MT-TW, MT-TV, MT-ND1, MT-ND2, MT-ND4, MT-ND5, MT-ND6 and MT-CO3. Abnormalities in mitochondrial energy generation result in neurodegenerative disorders like Leigh syndrome, which is characterized by an onset of symptoms between 12 months and three years of age. The symptoms frequently present themselves following a viral infection and include movement disorders and peripheral neuropathy, as well as hypotonia, spasticity and cerebellar ataxia. Roughly half of affected patients die of respiratory or cardiac failure by the age of three. Leigh syndrome is a maternally inherited disorder and its diagnosis is established through