The primary features displayed on a person with MERRF include myoclonus, seizures, cerebellar ataxia, myopathy, and ragged red fibers (RRF) on muscle biopsy, leading to the disease's name. (wikipedia.org)
It has been observed that patients with MERRF syndrome will primarily display myoclonus as a first symptom. (wikipedia.org)
MERRF is characterized by muscle twitches (myoclonus), weakness (myopathy), and progressive stiffness (spasticity). (medlineplus.gov)
abstract = "Myoclonus is a possible manifestation of mitochondrial disorders, and its presence is considered, in association with epilepsy and the ragged red fibers, pivotal for the syndromic diagnosis of MERRF (myoclonic epilepsy with ragged red fibers). (unicatt.it)
Finally, myoclonus is not inextricably linked to epilepsy in MERRF patients, but more to cerebellar ataxia. (unicatt.it)
Finally, this study reinforces the notion that myoclonus is not inextricably linked to epilepsy in MERRF patients, and therefore the term {"}myoclonic epilepsy{"} seems inadequate and potentially misleading. (unicatt.it)
The absence seizures involved in this syndrome are often prolonged, with bilateral limb myoclonus, differentiating it from idiopathic childhood absence seizures, for which seizure duration involves seconds and can be accompanied with only mild jerks of eyes, eyelids, or eyebrows. (medscape.com)
Specific syndromes of progressive myoclonic epilepsy with key clinical features include Unverricht-Lundborg disease (Baltic myoclonus), myoclonus epilepsy with ragged red fibers (MERRF), neuronal ceroid lipofuscinoses (Batten disease), and sialidoses (cherry-red spot myoclonus syndrome). (medscape.com)
Diagnosis and Management of Opsoclonus-Myoclonus-Ataxia Syndrome in Children: An International Perspective. (nih.gov)
Myoclonic7
MERRF syndrome (or myoclonic epilepsy with ragged red fibers) is a mitochondrial disease. (wikipedia.org)
Myoclonic epilepsy with ragged-red fibers (MERRF) is a disorder that affects many parts of the body, particularly the muscles and nervous system. (medlineplus.gov)
As mentioned above, a few individuals with a mutation in the MT-TH gene have features of both myoclonic epilepsy with ragged-red fibers (MERRF) and MELAS. (encyclopedia.pub)
In Ohtahara syndrome, tonic spasms are the dominant seizure type, with little to no myoclonic seizures. (medscape.com)
If myoclonic epilepsy with ragged red fibers (MERRF) syndrome is caused by at least one of four point mutations in mitochondrial DNA, then curing the disease should be as easy as giving new mitochondria to patients. (mitochondrialdiseasenews.com)
optic neuropathy) and MERRF (myoclonic epilepsy with ragged red fibers) are what kind of genetic disorder? (brainscape.com)
MELAS23
Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke (MELAS) syndrome is a multisystem and progressive neurodegenerative disorder. (medscape.com)
The typical presentation of patients with MELAS syndrome includes features that comprise the name of the disorder, such as mitochondrial encephalomyopathy, lactic acidosis , and strokelike episodes. (medscape.com)
Approximately 80% of patients with the clinical characteristics of MELAS syndrome have a heteroplasmic A-to-G point mutation in the dihydrouridine loop of the transfer RNA (tRNA) Leu (UUR) gene at base pair (bp) 3243 (ie, 3243 A → G mutation). (medscape.com)
The pathogenesis of the strokelike episodes in MELAS syndrome has not been completely elucidated. (medscape.com)
The multisystem dysfunction in patients with MELAS syndrome may be due to both parenchymal and vascular OXPHOS defects. (medscape.com)
The unusual strokelike episodes and higher morbidity observed in MELAS syndrome may be secondary to alterations in nitric oxide homeostasis that cause microvascular damage. (medscape.com)
Measurements of respiratory enzyme activities in intact mitochondria have revealed that more than one half of the patients with MELAS syndrome may have complex I or complex I + IV deficiency. (medscape.com)
Yet another pattern of regional metabolic abnormality was present in the MELAS syndrome, where proton spectroscopic imaging demonstrated focal localization of abnormally increased lactate/creatine and decreased N -acetylaspartate/creatine to the regions of the stroke-like lesions on conventional MR images. (neurology.org)
This combination of signs and symptoms is called MERRF/MELAS overlap syndrome. (encyclopedia.pub)
MT-TH gene mutations that cause MELAS and MERRF/MELAS overlap syndrome change single DNA building blocks (nucleotides) in the gene. (encyclopedia.pub)
Researchers have not determined how these genetic changes alter energy production in mitochondria or cause the varied signs and symptoms of MELAS or MERRF/MELAS overlap syndrome. (encyclopedia.pub)
It remains unknown why this mutation causes the overlapping features of MERRF and MELAS. (encyclopedia.pub)
First, MELAS and MERRF are completely different disorders, why simply the genotype can explain the difference between the two patients. (himjournals.com)
Novel mitochondrial DNA ND5 mutation in a patient with clinical features of MELAS and MERRF. (ima-press.net)
For individuals with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke (MELAS) syndrome and for those with other oxidative phosphorylation (OXPHOS) disorders, metabolic therapies are administered to increase the production of adenosine triphosphate (ATP) and to slow or arrest the deterioration of this condition and other mitochondrial encephalomyopathies. (medscape.com)
Arginine administration during the acute and interictal periods of the strokelike episodes of the MELAS syndrome may represent a potential new therapy to reduce brain damage due to mitochondrial dysfunction, and is one of the most promising therapies to date. (medscape.com)
Based on the hypothesis that the strokelike episodes in MELAS syndrome are triggered by impaired vasodilation in the intracerebral arteries due to decreased levels of circulating NO, elevation of arginine and NO levels may ameliorate this effect. (medscape.com)
In addition, L-arginine may modulate excitation by neurotransmitters at nerve endings and such effects might contribute to alleviation of strokelike symptoms in MELAS syndrome. (medscape.com)
In secondary carnitine deficiency associated with MELAS syndrome, carnitine may restore generation of free CoA and avoid carnitine depletion. (medscape.com)
If MELAS syndrome occurs associated with LCFAO defect, use of carnitine is debatable because it may enhance formation of long-chain acylcarnitines, which may cause ventricular arrhythmogenesis. (medscape.com)
Mutations12
The cause of MERRF disorder is due to mutations in the mitochondrial genome. (wikipedia.org)
Four point mutations in the genome can be identified that are associated with MERRF: m.A8344G, m.T8356C, m.G8361A, and m.G8363A. (wikipedia.org)
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. (wikipedia.org)
Mutations in the MT-TK gene are the most common cause of MERRF, occurring in more than 80 percent of all cases. (medlineplus.gov)
Less frequently, mutations in the MT-TL1 , MT-TH , and MT-TS1 genes have been reported to cause the signs and symptoms of MERRF. (medlineplus.gov)
People with mutations in the MT-TL1 , MT-TH , or MT-TS1 gene typically have signs and symptoms of other mitochondrial disorders as well as those of MERRF. (medlineplus.gov)
Mutations that cause MERRF impair the ability of mitochondria to make proteins, use oxygen, and produce energy. (medlineplus.gov)
A small percentage of MERRF cases are caused by mutations in other mitochondrial genes, and in some cases the cause of the condition is unknown. (medlineplus.gov)
Most cases of MERRF are maternally inherited due to mtDNA mutations. (rarediseasesnetwork.org)
Four other mitochondrial DNA mutations have been reported to cause MERRF. (rarediseasesnetwork.org)
MERRF syndrome is caused by mutations in mitochondrial DNA, which in sperm cells is typically lost during fertilisation, so all mtDNA comes from the mother. (thelilyfoundation.org.uk)
For example, Leigh syndrome is associated with over 30 gene mutations, making it difficult to use single-gene identification as a cost-effective means of pinpointing Leigh syndrome. (mitochondrialdiseasenews.com)
Seizures1
Other features of MERRF include recurrent seizures (epilepsy), difficulty coordinating movements (ataxia), a loss of sensation in the extremities (peripheral neuropathy), and slow deterioration of intellectual function (dementia). (medlineplus.gov)
Point mutation1
The point mutation m.A8344G is most commonly associated with MERRF, in a study published by Paul Jose Lorenzoni from the Department of neurology at University of Panama stated that 80% of the patients with MERRF disease exhibited this point mutation. (wikipedia.org)
Chronic progressive external ophthalmoplegia (CPEO) is the most common characteristic of Kearns-Sayre syndrome, which is one member of the family of mitochondrial myopathies. (mitochondrialdiseasenews.com)
MtDNA1
Researchers have not determined how changes in mtDNA lead to the specific signs and symptoms of MERRF. (medlineplus.gov)
Mitochondrial disorder2
The causes of MERRF syndrome are difficult to determine, but because it is a mitochondrial disorder, it can be caused by the mutation of nuclear DNA or mitochondrial DNA. (wikipedia.org)
Another unique moment, involved Dalia Flagert, a young girl with MERRF syndrome, a rare degenerative mitochondrial disorder that has left her in a wheelchair. (rareshare.org)
Diagnosis3
Lumpers" include virtually any type of SGE, whereas "splitters" require slow spike-wave complexes to make a diagnosis of Lennox-Gastaut syndrome. (medscape.com)
Challenges in diagnosis and understanding of natural history of polycystic ovary syndrome. (clinicalcases.eu)
Congenital central hypoventilation syndrome: diagnosis and management. (nih.gov)
Epilepsy2
Epilepsy syndromes that are included in the category of SGE are discussed below. (medscape.com)
Finsterer J. Photosensitive Epilepsy and Polycystic Ovary Syndrome as Manifestations of MERRF. (clinicalcases.eu)
Symptoms5
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. (wikipedia.org)
Due to the multiple symptoms presented by the individual, the severity of the syndrome is very difficult to evaluate. (wikipedia.org)
In most cases, people with MERRF inherit an altered mitochondrial gene from their mother, who may or may not show symptoms of the disorder. (medlineplus.gov)
The prognosis for MERRF varies widely depending on age of onset, type and severity of symptoms, organs involved, and other factors. (rarediseasesnetwork.org)
Even if two individuals are affected by the same disease, such as Leigh syndrome, they may not have identical symptoms or causes of disease. (mitochondrialdiseasenews.com)
Dementia3
Ragged-red fibers (a characteristic microscopic abnormality observed in muscle biopsy of patients with MERRF and other mitochondrial disorders) Additional manifestations may include: hearing loss, short stature, exercise intolerance, dementia, multiple lipomas (fat tumors under the skin), cardiac defects, eye abnormalities, and speech impairment. (rarediseasesnetwork.org)
Approximately 55 percent were felt to have a single progressive neurodegenerative etiology, predominantly Alzheimer disease (AD), frontotemporal dementia (FTD), dementia with Lewy bodies (DLB), dementia related to Parkinson disease (PD), and corticobasal degeneration (including corticobasal syndrome and many other phenotypes) [ 2 ]. (medilib.ir)
The remaining 45 percent of patients had the following etiologies: vascular-related cognitive change, alcohol-related cognitive change, Huntington disease (HD), cognitive impairment resulting from multiple sclerosis (MS), prion diseases, dementia related to Down syndrome (predominantly AD), and unknown/unclassified. (medilib.ir)
Disorder that affects1
Estrella Salazar is a 17-year-old science genius from Nezahualcoyotl, Mexico whose 25-year-old sister, Perla, was born with MERRF syndrome, a rare disorder that affects the nervous system and can cause issues with hearing and mobility. (hiplatina.com)
Phenotypes1
The regional brain metabolic abnormalities in patients with these syndromes showed different features consistent with the distinct phenotypes. (neurology.org)
Affects2
MERRF syndrome affects different parts of the body, particularly the muscles and nervous system. (wikipedia.org)
For Harry's mother Mandy Norris, finding out that her son had MERRF syndrome, a mitochondrial disease that affects the muscles and nervous system, came with the added blow of learning that he had inherited the causal gene from her. (thelilyfoundation.org.uk)
A8344G1
The most common MERRF mutation is A8344G, which accounted for over 80% of the cases (GeneReview article). (rarediseasesnetwork.org)
Disorders5
Mitochondrial disorders, including MERRF, may present at any age. (wikipedia.org)
MERRF is part of a group of conditions known as mitochondrial disorders, which affect an estimated 1 in 5,000 people worldwide. (medlineplus.gov)
Mitochondrial DNA Depletion Syndrome (MDDS) is a group of autosomal recessive disorders that can lead to a significant reduction in the amount of mitochondrial DNA in affected tissues (e.g. muscle, liver, brain). (mitochondrialdisease.nhs.uk)
Manifestations1
The clinical manifestations of PCOS can be exacerbated by post-COVID syndrome. (clinicalcases.eu)
Gene2
Less commonly, the disorder results from a new mutation in a mitochondrial gene and occurs in people with no family history of MERRF. (medlineplus.gov)
The mutation involved in this overlap syndrome replaces the nucleotide guanine with the nucleotide adenine at gene position 12147 (written as G12147A). (encyclopedia.pub)
Commonly1
Less commonly, people with MERRF develop fatty tumors, called lipomas, just under the surface of the skin. (medlineplus.gov)
Patients3
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. (wikipedia.org)
In MERRF, only one of four patients showed an increase in the lactate/creatine resonance intensity ratio (an index of impairment of oxidative metabolism) in spectra from central (supraventricular) or occipital brain volumes, and this was small. (neurology.org)
Patients with traumatic brain injury, Down syndrome, and certain types of vascular disease are major patient groups that may or may not be included in these studies. (medilib.ir)
Genetic4
Harry had his genetic blood test there in August 2016, and in November we got confirmation that yes, it was MERRF. (thelilyfoundation.org.uk)
The etiology of polycystic ovary syndrome (PCOS) is not exactly known, but there are indications that genetic factors, exposure to androgen in early childhood, and obesity lead to a disruption of the hypothalamic-pituitary-ovarian axis and dysregulation of microRNAs. (clinicalcases.eu)
Trisomy 21 (down syndrome) is an example of what kind of genetic disorder? (brainscape.com)