MERRF syndrome

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MERRF syndrome
Other namesFukuhara syndrome
"ragged red fibers" in MERRF syndrome
SpecialtyNeurology Edit this on Wikidata

MERRF syndrome (or myoclonic epilepsy with ragged red fibers) is a

multiple lipomata. Mitochondrial disorders, including MERRFS, may present at any age.[4]

Symptoms and signs

An individual displaying MERRFs syndrome will manifest not only a single symptom, but patients regularly display more than one affected body part at a time. It has been observed that patients with MERRF syndrome will primarily display

multiple lipomata, and/or cardiomyopathy with Wolff Parkinson-White syndrome. Most patients will not exhibit all of these symptoms, but more than one of these symptoms will be present in a patient who has been diagnosed with MERRF disease. Mitochondrial disorders, including MERRF, may present at any age.[4] Due to the multiple symptoms presented by the individual, the severity of the syndrome is very difficult to evaluate.[5]

Causes

Mitochondrial inheritance

The cause of MERRF disorder is due to

tRNA-Lys. This disrupts the synthesis of proteins. The remaining mutations only account for 10% of cases, and the remaining 10% of the patients with MERRF did not have an identifiable mutation in the mitochondrial DNA.[citation needed
]

Many genes are involved.[8] These genes include:

It involves the following characteristics:

  • progressive myoclonic epilepsy
  • "Ragged Red Fibers" - clumps of diseased
    mitochondria accumulate in the subsarcolemmal region of the muscle fiber and appear as "Ragged Red Fibers" when muscle is stained with modified Gömöri trichrome stain
    .

There is currently no cure for MERRF.[citation needed]

Mechanism

The mechanism by which MERRFs syndrome occur is not yet well understood. The human mitochondrial

muscle fiber.[6] These may extend throughout the muscle fiber as the disease severity increases. The mitochondrial aggregates cause the contour of the muscle fiber to become irregular, leading to the "ragged" appearance.[3]

Diagnosis

The diagnosis varies from individual to individual. Each is evaluated and diagnosed according to age, clinical phenotype, and pressed inheritance pattern.[14] If the individual has been experiencing myoclonus, the doctor will run a series of genetic studies to determine if it is a mitochondrial disorder.[citation needed]

The molecular

genetic studies are run to identify the reason of for the mutations underlying the mitochondrial dysfunction. This approach will avoid the need for a muscle biopsy or an exhaustive metabolic evaluation. After sequencing the mitochondrial genomes, four points mutations in the genome can be identified which are associated with MERRF: A8344G, T8356C, G8361A, and G8363A. The point mutation[9] A8344G is mostly associated with MERRF,[6] in a study published by Paul Jose Lorenzoni from the Department of neurology at University of Panama[7] stated that 80% of the patients with MERRF disease exhibited this point mutation. The remaining mutations only account for 10% of cases, and the remaining 10% of the patients with MERRF did not have an identifiable mutation in the mitochondrial DNA.[12]

If a patient does not exhibit mitochondrial DNA mutations, there are other ways that they can be diagnosed with MERRF. They can go through

computed tomography (CT) or magnetic resonance imaging (MRI).The classification for the severity of MERRF syndrome is difficult to distinguish since most individuals will exhibit multi-symptoms.[12] This is often necessary for children with complex neurologic or multi-system involvement, as described below.[4]

History and physical examination of the patient

A detailed family history should be obtained from at least three generations, particularly if there have been any

neuropathy and dysautonomia, or heart conditions such as cardiomyopathy. The patient's history might also exhibit kidney problems, such as proximal nephron dysfunction. There may also be endocrine conditions, such as diabetes or hypoparathyroidism. The patient might have also had a gastrointestinal condition which could have been due to liver disease, as well as episodes of nausea or vomiting. Multiple lipomas in the skin, sideroblastic anemia and pancytopenia in the metabolic system, or short stature might all be examples of patients with possible symptoms of MERRF disease.[citation needed
]

Treatment

Like many

diabetes, deafness, or cardiac disease, are treated in combination to manage symptoms.[citation needed
]

Research

The Journal of Child Neurology published a paper in 2011 that discusses possible new methods to test for MERRF and other mitochondrial diseases through a simple swabbing technique. This is a less invasive technique which allows for an analysis of buccal mitochondrial DNA, and showed significant amounts of the common 5 kb and 7.4 kb mitochondrial DNA deletions, which are also detectable in blood.[16] This study suggests that a buccal swab approach can be used to informatively examine mitochondrial dysfunction in children with seizures and may be applicable to screening mitochondrial disease with other clinical presentations.[citation needed]

The Proceedings of the

anticodon mutation, which solely affected aminoacylation.[12]

Society and culture

MERRF syndrome was the final diagnosis of seventh episode of third season on the show

House, M.D.
.

See also

References

  1. ^ Gene Reviews: MERRF
  2. PMID 20301693
    .
  3. ^
    PMID 20301403
    .
  4. ^ a b c "Mitochondrial myopathies: Clinical features and diagnosis". www.uptodate.com. Retrieved 2017-11-07.
  5. ^
    S2CID 9418186
    .
  6. ^ a b c "Myoclonus Epilepsy Associated with Ragged-Red Fibers (MERRF) Diagnosis Discussed by Researchers - Mitochondrial Disease News". Mitochondrial Disease News. 2015-05-04. Retrieved 2017-11-08.
  7. ^
    PMID 25337734
    .
  8. ^ Online Mendelian Inheritance in Man (OMIM): MYOCLONIC EPILEPSY ASSOCIATED WITH RAGGED-RED FIBERS; MERRF - 545000
  9. ^
    S2CID 22766360
    .
  10. PMID 7669057
    .
  11. S2CID 12423569
    .
  12. ^
    PMID 17878308
    .
  13. S2CID 12265373
    .
  14. ^ a b "Mitochondrial myopathies: Clinical features and diagnosis". www.uptodate.com. Retrieved 2017-11-08.
  15. ^ Gene reviews: MERRF: Management of patients
  16. S2CID 23912193
    .

External links
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