Term
Leber Hereditary Optic Neuropathy (LHON)mutation/alteration |
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Definition
Point mutation in protein coding genes (90% of cases in NAD1, 4 or 6) leading to decrease in ATP production |
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Term
Leber Hereditary Optic Neuropathy (LHON) gene locus |
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Definition
ND1, ND4 and ND6 various other mt DNAgenes |
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Term
Leber Hereditary Optic Neuropathy (LHON) gene product |
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Definition
NADH dehydrogenase 1, 4 and 6 subunits (complex I components) |
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Term
Leber Hereditary Optic Neuropathy (LHON) inheritance |
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Definition
Mitochondrial inheritance (maternal) Heteroplasmy is rare and disease expession is pretty uniform |
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Term
Leber Hereditary Optic Neuropathy (LHON) clinical features |
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Definition
Progressive bilateral, painless visual failure that develops in young adult. Males are more likely affected for unknown reasons. Selective degeneration of the retinal ganglion cell layer and optic nerve. Other features may include cardiac arrhythmias, postural tremor and movement disorders. |
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Term
Myoclonic Epilepsy Ragged‐Red Fibers (MERRF) gene/locus |
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Definition
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Term
Myoclonic Epilepsy Ragged‐Red Fibers (MERRF) gene product |
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Definition
transfert RNA for Lysine NADH dehydrogenase 5 subunit |
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Term
Myoclonic Epilepsy Ragged‐Red Fibers (MERRF) mutation/alteration |
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Definition
Point mutation in tRNA lys 90% of cases (causing premature termination of translation process for complex I and cytochrome oxidase) Point mutation in NADH dehydrogenase 5 subunit |
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Term
Myoclonic Epilepsy Ragged‐Red Fibers (MERRF) inheritance |
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Definition
Mitochondrial inheritance (maternal) Heteroplasmy common leading to variable expression of the disease |
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Term
Myoclonic Epilepsy Ragged‐Red Fibers (MERRF) clinical presentation |
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Definition
Myoclonus (muscle twitching), seizures, cerebellar ataxia, dementia, abnormal mitochondria in skeletal muscle that impart an irregular shape and bloddy red staining of the muscle cells. Some mitochondria contain parking lot inclusions |
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Term
Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke like Episodes syndrome (MELAS) gene locus |
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Definition
tRNA (leu) gene various ND genes |
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Term
Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke like Episodes syndrome (MELAS) gene product |
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Definition
transfert RNA for leucine various NADH dehydrogenase subunits |
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Term
Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke like Episodes syndrome (MELAS) mutation/alteration |
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Definition
Point mutation in tRNAleu 80% of cases(causing premature termination of translation process for cytochrome oxidase i.e complexIV) Point mutation in NADH dehydrogenase 5 subunit |
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Term
Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke like Episodes syndrome (MELAS) inheritance |
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Definition
Mitochondrial inheritance (maternal) Heteroplasmy common leading to variable expression of the disease |
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Term
Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke like Episodes syndrome (MELAS) clinical presentation |
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Definition
Mitochondrial myopathy evidenced by lactic acidosis, encephalopathy with seizures/dementia, stroke like episodes |
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Term
Kearns‐Sayre syndrome gene locus |
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Definition
Partial deletions and duplications of mtDNA |
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Term
Kearns‐Sayre syndrome mutation/alteration |
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Definition
Partial deletions and duplications of mtDNA resulting in decrease activity of complexes I‐IV |
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Term
Kearns‐Sayre syndrome inheritance |
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Definition
Mitochondrial inheritance (maternal) Heteroplasmy common leading to variable expression of the disease |
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Term
Kearns‐Sayre syndrome clinical presentation |
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Definition
Chronic progessive external ophthalmoplegia (paralysis of the muscle controlling the eyes),pigmentary degeneration of the retina, hearing loss, vestibular dysfunction, cerebellar ataxia and onset around 20 years of age |
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Term
Leigh syndrome inheritance |
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Definition
Mendelian inheritance (AR) for mutations in nuclear genes Mitochondrial inheritance (maternal) Heteroplasmy common for mutation in mtDNA |
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Term
Leigh syndrome mutation/alteration |
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Definition
point mutation in protein genes and RNA genes |
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Term
Leigh syndrome gene locus |
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Definition
various mutations in nuclear DNA and mtDNA (including ND genes, mitochondrial tRNA genes and ATP synthetase 6 (ATP6) gene). |
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Term
Leigh syndrome clinical presentation |
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Definition
Disease of early childhood, lactic acidosis, arrest of psychomotor development, feeding problems, seizures, extraoccular palsies and weakness with hypotonia. Death within 1 to 2 years |
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