MELAS mitochondrial

The condition known as fatal infantile mitochondrial myopathy and renal dysfunction involves severe diminution or absence of most oxidoreductases of the respiratory chain. MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke) is an inherited condition due to NADHiubiquinone oxidoreductase (complex I) or cytochrome oxidase deficiency. It is caused by a muta-... 

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke like episodes (MELAS) Mitochondrial tRNA (leu)... 

MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) resuits from a point mutation in the mitochondriai tRNA gene. 

The clinical symptoms of mitochondrial diseases are highly varied and include seizures, vomiting, deafness, dementia, stroke-like episodes, and short stature. Although there are many types of mitochondrial disorders, four of the most common types are as follows Kearns-Sayre syndrome, Leber s hereditary optic atrophy, MELAS (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes) and MERRE (myoclonic epilepsy with ragged red fibres). 

MELAS, Mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes CPEO, chronic progressive external ophthalmoplegia LHON, Leber hereditary optic neuropathy NARP, neurogenic muscle weakness, ataxia, and retinitis pigmentosa NIDDM, non-insulin-dependent diabetes mellitus TER, termination. 

Figure 8-4. The effect of the MELAS mutation on mitochondrial function is to interfere with function of respiratory Complex I or I and IV, leading to increased levels of NADH and thus also of lactate. CoQ, coenzyme Q MELAS, mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes RC, respiratory complex.

Figure 8-7. MELAS (mitochondrial encephalomy-opathy, lactic acidosis, and strokelike episodes) assay using restriction enzyme Apa I to detect the presence of mutant mtDNA in skeletal muscle biopsies. GM, grandmother M, mother R proband U, maternal uncle. The uncut PCR product is 372 bp. The presence of the MELAS mutation results in cleavage into 263- and 109-bp fragments.

MELAS (mitochondrial myopathy, encephalo-myopathy, lactic acidosis, and stroke-like episodes) Progressive neurodengenerative disease characterized by stoke-like episodes first occurring between 5 and 15 years of age and a mitochondrial myopathy 80-90% mutations in tRNA "... 

MELAS Mitochondrial encephalopathy, lactic acidosis, stroke-like episodes... 

MELAS (mitochondrial myopathy. Finger nails (see nails) 580, i... 

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