Term
Leber Hereditary Optic
Neuropathy (LHON)mutation/alteration |
|
Definition
Point mutation in protein
coding genes (90% of cases in
NAD1, 4 or 6) leading to
decrease in ATP production |
|
|
Term
Leber Hereditary Optic
Neuropathy (LHON) gene locus |
|
Definition
ND1, ND4 and ND6
various other
mt DNAgenes |
|
|
Term
Leber Hereditary Optic
Neuropathy (LHON) gene product |
|
Definition
NADH dehydrogenase 1,
4 and 6 subunits
(complex I components) |
|
|
Term
Leber Hereditary Optic
Neuropathy (LHON) inheritance |
|
Definition
Mitochondrial inheritance
(maternal)
Heteroplasmy is rare and
disease expession is pretty
uniform |
|
|
Term
Leber Hereditary Optic
Neuropathy (LHON) clinical features |
|
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. |
|
|
Term
Myoclonic Epilepsy
Ragged‐Red Fibers (MERRF) gene/locus |
|
Definition
|
|
Term
Myoclonic Epilepsy
Ragged‐Red Fibers
(MERRF) gene product |
|
Definition
transfert RNA for Lysine
NADH dehydrogenase 5
subunit |
|
|
Term
Myoclonic Epilepsy
Ragged‐Red Fibers
(MERRF) mutation/alteration |
|
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 |
|
|
Term
Myoclonic Epilepsy
Ragged‐Red Fibers
(MERRF) inheritance |
|
Definition
Mitochondrial inheritance
(maternal) Heteroplasmy
common leading to
variable expression of the
disease |
|
|
Term
Myoclonic Epilepsy
Ragged‐Red Fibers
(MERRF) clinical presentation |
|
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 |
|
|
Term
Mitochondrial Myopathy,
Encephalopathy, Lactic
Acidosis and Stroke like
Episodes syndrome
(MELAS) gene locus |
|
Definition
tRNA (leu) gene
various ND genes |
|
|
Term
Mitochondrial Myopathy,
Encephalopathy, Lactic
Acidosis and Stroke like
Episodes syndrome
(MELAS) gene product |
|
Definition
transfert RNA for leucine
various NADH
dehydrogenase subunits |
|
|
Term
Mitochondrial Myopathy,
Encephalopathy, Lactic
Acidosis and Stroke like
Episodes syndrome
(MELAS) mutation/alteration |
|
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 |
|
|
Term
Mitochondrial Myopathy,
Encephalopathy, Lactic
Acidosis and Stroke like
Episodes syndrome
(MELAS) inheritance |
|
Definition
Mitochondrial inheritance
(maternal) Heteroplasmy
common leading to
variable expression of the
disease |
|
|
Term
Mitochondrial Myopathy,
Encephalopathy, Lactic
Acidosis and Stroke like
Episodes syndrome
(MELAS) clinical presentation |
|
Definition
Mitochondrial myopathy evidenced by
lactic acidosis, encephalopathy with
seizures/dementia, stroke like episodes |
|
|
Term
| Kearns‐Sayre syndrome gene locus |
|
Definition
Partial deletions and
duplications of mtDNA |
|
|
Term
| Kearns‐Sayre syndrome mutation/alteration |
|
Definition
Partial deletions and
duplications of mtDNA
resulting in decrease activity
of complexes I‐IV |
|
|
Term
| Kearns‐Sayre syndrome inheritance |
|
Definition
Mitochondrial inheritance
(maternal) Heteroplasmy
common leading to
variable expression of the
disease |
|
|
Term
| Kearns‐Sayre syndrome clinical presentation |
|
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 |
|
|
Term
| Leigh syndrome inheritance |
|
Definition
Mendelian inheritance
(AR) for mutations in
nuclear genes
Mitochondrial
inheritance (maternal)
Heteroplasmy common
for mutation in mtDNA |
|
|
Term
| Leigh syndrome mutation/alteration |
|
Definition
point mutation in protein
genes and RNA genes |
|
|
Term
| Leigh syndrome gene locus |
|
Definition
various mutations in
nuclear DNA and mtDNA
(including ND genes,
mitochondrial tRNA genes
and ATP synthetase 6
(ATP6) gene). |
|
|
Term
| Leigh syndrome clinical presentation |
|
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 |
|
|
