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Like many mitochondrial diseases, there is no cure for MERRF, no matter the means for diagnosis of the disease. The treatment is primarily symptomatic. High doses of Coenzyme Q10, B complex vitamins and L-Carnitine are the drugs that patients are treated with in order to account for the altered metabolic processed resulting in the disease. There is very little success with these treatments as therapies in hopes of improving mitochondrial function. The treatment only alleviates symptoms and these do not prevent the disease from progressing. Patients with concomitant disease, such as diabetes, deafness or cardiac disease, are treated in combination to manage symptoms.
Treatment for MSS is symptomatic and supportive including physical and occupational therapy, speech therapy, and special education. Cataracts must be removed when vision is impaired, generally in the first decade of life. Hormone replacement therapy is needed if hypogonadism is present.
The treatment of genetic disorders is an ongoing battle with over 1800 gene therapy clinical trials having been completed, are ongoing, or have been approved worldwide. Despite this, most treatment options revolve around treating the symptoms of the disorders in an attempt to improve patient quality of life.
Gene therapy refers to a form of treatment where a healthy gene is introduced to a patient. This should alleviate the defect caused by a faulty gene or slow the progression of disease. A major obstacle has been the delivery of genes to the appropriate cell, tissue, and organ affected by the disorder. How does one introduce a gene into the potentially trillions of cells which carry the defective copy? This question has been the roadblock between understanding the genetic disorder and correcting the genetic disorder.
NARP syndrome is not curable. Symptomatic relief is targeted. Antioxidants play a role in improving the oxidative phosphorylation that is otherwise impaired.
Although research is ongoing, treatment options are currently limited; vitamins are frequently prescribed, though the evidence for their effectiveness is limited.
Pyruvate has been proposed in 2007 as a treatment option. N-acetyl cysteine reverses many models of mitochondrial dysfunction.. In the case of mood disorders, specifically bipolar disorder, it is hypothesized that N-acetyl-cysteine (NAC), acetyl-L-carnitine (ALCAR), S-adenosylmethionine (SAMe), coenzyme Q10 (CoQ10), alpha-lipoic acid (ALA), creatine monohydrate (CM), and melatonin could be potential treatment options.
Succinic acid has been used successfully to treat MELAS syndrome, and also Leighs disease. Patients are managed according to what areas of the body are affected at a particular time. Enzymes, amino acids, antioxidants and vitamins have been used.
Also the following supplements may help:
- CoQ10 has been helpful for some MELAS patients. Nicotinamide has been used because complex l accepts electrons from NADH and ultimately transfers electrons to CoQ10.
- Riboflavin has been reported to improve the function of a patient with complex l deficiency and the 3250T-C mutation.
- The administration of L-arginine during the acute and interictal periods may represent a potential new therapy for this syndrome to reduce brain damage due to impairment of vasodilation in intracerebral arteries due to nitric oxide depletion.
- There is also a case report where succinate was successfully used to treat uncontrolled convulsions in MELAS patients, although this treatment modality is yet to be thoroughly investigated or widely recommended.
Currently there is no curative treatment for KSS. Because it is a rare condition, there are only case reports of treatments with very little data to support their effectiveness. Several promising discoveries have been reported which may support the discovery of new treatments with further research. Satellite cells are responsible for muscle fiber regeneration. It has been noted that mutant mtDNA is rare or undetectable in satellite cells cultured from patients with KSS. Shoubridge et al. (1997) asked the question whether wildtype mtDNA could be restored to muscle tissue by encouraging muscle regeneration. In the forementioned study, regenerating muscle fibers were sampled at the original biopsy site, and it was found that they were essentially homoplasmic for wildtype mtDNA. Perhaps with future techniques of promoting muscle cell regeneration and satellite cell proliferation, functional status in KSS patients could be greatly improved.
One study described a patient with KSS who had reduced serum levels of coenzyme Q10. Administration of 60–120 mg of Coenzyme Q10 for 3 months resulted in normalization of lactate and pyruvate levels, improvement of previously diagnosed first degree AV block, and improvement of ocular movements.
A screening ECG is recommended in all patients presenting with CPEO. In KSS, implantation of pacemaker is advised following the development of significant conduction disease, even in asymptomatic patients.
Screening for endocrinologic disorders should be performed, including measuring serum glucose levels, thyroid function tests, calcium and magnesium levels, and serum electrolyte levels. Hyperaldosteronism is seen in 3% of KSS patients.
Nucleoside bypass therapy is an experimental treatment aimed to restore the normal levels of deoxyribonucleotides (dNTPs) in mitochondria.
Spindle transfer, where the nuclear DNA is transferred to another healthy egg cell leaving the defective mitochondrial DNA behind, is a potential treatment procedure that has been successfully carried out on monkeys. Using a similar pronuclear transfer technique, researchers at Newcastle University led by Douglass Turnbull successfully transplanted healthy DNA in human eggs from women with mitochondrial disease into the eggs of women donors who were unaffected. In such cases, ethical questions have been raised regarding biological motherhood, since the child receives genes and gene regulatory molecules from two different women. Using genetic engineering in attempts to produce babies free of mitochondrial disease is controversial in some circles and raises important ethical issues. A male baby was born in Mexico in 2016 from a mother with Leigh syndrome using spindle transfer.
In September 2012 a public consultation was launched in the UK to explore the ethical issues involved. Human genetic engineering was used on a small scale to allow infertile women with genetic defects in their mitochondria to have children.
In June 2013, the United Kingdom government agreed to develop legislation that would legalize the 'three-person IVF' procedure as a treatment to fix or eliminate mitochondrial diseases that are passed on from mother to child. The procedure could be offered from 29 October 2015 once regulations had been established.
Embryonic mitochondrial transplant and protofection have been proposed as a possible treatment for inherited mitochondrial disease, and allotopic expression of mitochondrial proteins as a radical treatment for mtDNA mutation load.
Currently, human clinical trials are underway at GenSight Biologics (ClinicalTrials.gov # NCT02064569) and the University of Miami (ClinicalTrials.gov # NCT02161380) to examine the safety and efficacy of mitochondrial gene therapy in Leber's hereditary optic neuropathy.
There are no treatments for MDDS, but some of the symptoms can be managed. For survivors living with MDDS, there are drugs to control epilepsy, and physical therapy can help with muscle control. Liver transplants may benefit people with liver involvement.
Not all genetic disorders directly result in death, however there are no known cures for genetic disorders. Many genetic disorders affect stages of development such as Down syndrome. While others result in purely physical symptoms such as muscular dystrophy. Other disorders, such as Huntington's disease show no signs until adulthood. During the active time of a genetic disorder, patients mostly rely on maintaining or slowing the degradation of quality of life and maintain patient autonomy. This includes physical therapy, pain management, and may include a selection of alternative medicine programs.
There is no cure for Alström syndrome; however, there are treatment aims to reduce the symptoms and prevent further complications. Some of these treatment aims include:
- Corrective lenses: tinted lenses that help with the sensitivity from bright lights. The patients may have to adapt to reading in Braille, use adaptive equipment, mobility aids, and adaptive computing skills.
- Education: patients with Alström syndrome suffering from intellectual disabilities must have access to education. They must be able to receive free and appropriate education. Some Alström syndrome patients are educated in normal classrooms. Other patients have to take special education classes or attend to specialized schools that are prepared to teach children with disabilities. Staff members from schools have to consult with patient's parents or caregivers in order to design an education plan based on the child's needs. In addition, the school may document the progress of the child in order to confirm that the child's needs are being met.
- Hearing aids: the battery-operated devices are available in three styles: behind the ear, in the ear, and inside the ear canal. Behind the ear aims for mild-to-profound hearing loss. In the ear aims for mild to severe hearing loss. Lastly, the canal device is aimed for mild to moderately severe hearing loss. Patients that have severe hearing loss may benefit from a cochlear implant.
- Diet: an appropriate and healthy diet is necessary for individuals with Alström syndrome because it could potentially decreases chances of obesity or diabetes.
- Occupational therapy: the therapist helps the child learn skills to help him or her perform basic daily tasks like eating, getting dressed, and communicating with others.
- Physical Activity: exercising reduces chances of being obese and helping control blood sugar levels.
- Dialysis: helps restore filtering function. With hemodialysis, a patient's blood circulates into an external filter and clean. The filtered blood is then returned into the body. With peritoneal dialysis, fluid containing dextrose is introduced into the abdomen by a tube. The solution then absorbs the wastes into the body and is then removed.
- Transplantation: patients that endure a kidney failure may undergo a kidney transplantation.
- Surgery: if the patient endures severe scoliosis or kyphosis, surgery may be required.
The severity and prognosis vary with the type of mutation involved.
Although no cure currently exists, there is hope in treatment for this class of hereditary diseases with the use of an embryonic mitochondrial transplant.
Succinic acid has been studied, and shown effective for both Leighs disease, and MELAS syndrome. If the mutation is in succinate dehydrogenase then there is a build up of succinate, in which case succinic acid won't work so the treatment is with fumaric acid to replace the fumarate than can not be made from succinate. A high-fat, low-carbohydrate diet may be followed if a gene on the X chromosome is implicated in an individual's Leigh syndrome. Thiamine (vitamin B) may be given if a deficiency of pyruvate dehydrogenase is known or suspected. The symptoms of lactic acidosis are treated by supplementing the diet with sodium bicarbonate (baking soda) or sodium citrate, but these substances do not treat the cause of Leigh syndrome. Dichloroacetate may also be effective in treating Leigh syndrome-associated lactic acidosis; research is ongoing on this substance. Coenzyme Q10 supplements have been seen to improve symptoms in some cases.
Clinical trials of the drug EPI-743 for Leigh disease are ongoing.
In 2016, John Zhang and his team at New Hope Fertility Center in New York, USA, performed a spindle transfer mitochondrial donation technique on a mother in Mexico who was at risk of producing a baby with Leigh disease. A healthy boy was born on 6 April 2016. However, it is not yet certain if the technique is completely reliable and safe.
Treatments include discontinuation of protein intake, intravenous infusion of glucose and, as needed, infusion of supplemental arginine and the ammonia removal drugs, sodium phenylacetate and sodium benzoate.
There is no known direct treatment. Current treatment efforts focus on managing the complications of Wolfram syndrome, such as diabetes mellitus and diabetes insipidus.
Idebenone is a short-chain benzoquinone that interacts with the mitochondrial electron transport chain to enhance cellular respiration. When used in individuals with LHON, it is believed to allow electrons to bypass the dysfunctional complex I. Successful treatment using idebenone was initially reported in a small number of patients.
Two large-scale studies have demonstrated the benefits of idebenone. The Rescue of Hereditary Optic Disease Outpatient Study (RHODOS) evaluated the effects of idebenone in 85 patients with LHON who had lost vision within the prior five years. In this study, the group taking idebenone 900 mg per day for 24 weeks showed a slight improvement in visual acuity compared to the placebo group, though this difference was not statistically significant. Importantly, however, patients taking idebenone were protected from further vision loss, whereas the placebo group had a steady decline in visual acuity. Further, individuals taking idebenone demonstrated preservation of color vision and persistence of the effects of idebenone 30 months after discontinuing therapy. A retrospective analysis of 103 LHON patients by Carelli et al. builds upon these results. This study highlighted that 44 subjects who were treated with idebenone within one year of onset of vision loss had better outcomes, and, further, that these improvements with idebenone persisted for years.
Idebenone, combined with avoidance of smoke and limitation of alcohol intake, is the preferred standard treatment protocol for patients affected by LHON. Idebenone doses are prescribed to be taken spaced out throughout the day, rather than all at one time. For example, to achieve a dose of 900 mg per day, patients take 300 mg three times daily with meals. Idebenone is fat soluble, and may be taken with a moderate amount of dietary fat in each meal to promote absorption. It is recommended that patients on idebenone also take vitamin C 500 mg daily to keep idebenone in its reduced form, as it is most active in this state.
The journal of child neurology published a paper in 2012, Buccal swab analysis of mitochondrial enzyme deficiency and DNA defects in a child with suspected myoclonic epilepsy and ragged red fibers (MERRF), discusses possible new methods to test for MERRF and other mitochondrial diseases, through a simple swabbing technique. This is a less invasive techniques 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, also detectable in blood. 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.
Proceedings of the National Academy of Science of the United States of America published an article in 2007 which investigate the human mitochondrial tRNA (hmt-tRNA) mutations which are associated with mitochondrial myopathies. Since the current understanding of the precise molecular mechanisms of these mutations is limited, there is no efficient method to treat their associated mitochondrial diseases. All pathogenic mutants displayed pleiotropic phenotypes, with the exception of the G34A anticodon mutation, which solely affected aminoacylation.
There is no treatment for MKD. But, the inflammation and the other effects can be reduced to a certain extent.
- IL-1 targeting drugs can be used to reduce the effects of the disorder. Anakinra is antagonist to IL-1 receptors. Anakinra binds the IL-1 receptor, preventing the actions of both IL-1α and IL-1β, and it has been proved to reduce the clinical and biochemical inflammation in MKD. It can effectively decreases the frequency as well as the severity of inflammatory attacks when used on a daily basis. Disadvantages with the usage of this drug are occurrence of painful injection site reaction and as the drug is discontinued in the near future the febrile attacks start. (Examined in a 12-year-old patient).
- Canakinumab is a long acting monoclonal antibody which is directed against IL-1β has shown to be effective in reducing both frequency and severity in patients suffering from mild and severe MKD in case reports and observational case series. It reduces the physiological effects but the biochemical parameter still remain elevated (Galeotti et al. demonstrated that it is more effective than anakinra –considered 6 patients suffering from MKD).
- Anti-TNF therapy might be effective in MKD, but the effect is mostly partial and therapy failure and clinical deterioration have been described frequently in patients on infliximab or etanercept. A beneficial effect of human monoclonal anti-TNFα antibody adalimumab was seen in a small number of MKD patients.
- Most MKD patients are benefited by anti-IL-1 therapy. However, anti-IL-1-resistant disease may also occur. Example. tocilizumab (a humanized monoclonal antibody against the interleukin-6 (IL-6) receptor). This drug is used when the patients are unresponsive towards Anakinra. (Shendi et al. treated a young woman in whom anakinra was ineffective with tocilizumab). It was found that it was effective in reducing the biochemical and clinical inflammation [30].Stoffels et al. observed reduction of frequency and severity of the inflammatory attacks, although after several months of treatment one of these two patients persistently showed mild inflammatory symptoms in the absence of biochemical inflammatory markers.
- A beneficial effect of hematopoietic stem cell transplantation can be used in severe mevalonate kinase deficiency conditions (Improvement of cerebral myelinisation on MRI after allogenic stem cell transplantation was observed in one girl). But, liver transplantation did not influence febrile attacks in this patient.
There is currently no defined treatment to ameliorate the muscle weakness of CPEO. Treatments used to treat other pathologies causing ophthalmoplegia has not been shown to be effective.
Experimental treatment with tetracycline has been used to improve ocular motility in one patient. Coenzyme Q has also been used to treat this condition. However, most neuro-ophthalmologists do not ascribe to any treatment.
Ptosis associated with CPEO may be corrected with surgery to raise the lids, however due to weakness of the orbicularis oculi muscles, care must be taken not to raise the lids in excess causing an inability to close the lids. This results in an exposure keratopathy. Therefore, rarely should lid surgery be performed and only by a neuro-ophthalmologist familiar with the disease.
The most common strabismus finding is large angle exotropia which can be treated by maximal bilateral eye surgery, but due to the progressive nature of the disease, strabismus may recur. Those that have diplopia as a result of asymmetric ophthalmoplegia may be corrected with prisms or with surgery to create a better alignment of the eyes.
Standard of care for treatment of CPT II deficiency commonly involves limitations on prolonged strenuous activity and the following dietary stipulations:
- The medium-chain fatty acid triheptanoin appears to be an effective therapy for adult-onset CPT II deficiency.
- Restriction of lipid intake
- Avoidance of fasting situations
- Dietary modifications including replacement of long-chain with medium-chain triglycerides supplemented with L-carnitine
Treatment is dependent upon diagnosis and the stage at which the diagnosis is secured. For toxic and nutritional optic neuropathies, the most important course is to remove the offending agent if possible and to replace the missing nutritional elements, orally, intramuscularly, or intravenously. If treatment is delayed, the injury may be irreversible. The course of treatment varies with the congenital forms of these neuropathies. There are some drug treatments that have shown modest success, such as Idebenone used to treat LOHN. Often treatment is relegated to lifestyle alterations and accommodations and supportive measures.
At this time there is no treatment for transaldolase deficiency.
There is currently research being done to find treatments for transaldolase deficiency. A study done in 2009 used orally administered N-acetylcysteine on transaldolase deficient mice and it prevented the symptoms associated with the disease. N-acetylcysteine is a precursor for reduced glutathione, which is decreased in transaldolase deficient patients.
Research for designing therapeutic trials is ongoing via the Washington University Wolfram Study Group, supported by The Ellie White Foundation for Rare Genetic Disorders and The Jack and J.T. Snow Scientific Research Foundation for Wolfram research.