In terms of treatment the following are done to manage the IPEX syndrome in those affected individuals(corticosteroids are the first treatment that is used):

- TPN(nutritional purpose)

- Cyclosporin A and FK506

- Sirolimus(should FK506 prove non-effective)

- Granulocyte colony stimulating factor

- Bone marrow transplant

- Rituximab

The most common method to manage hypoglycemia and diabetes is with an insulin pump. . However in infants and very young children long acting insulins like Glargine and Levemir are preferred to prevent recurrent hypoglycemia . As soon as parent knows Walcott-Rallison syndrome is the source, treatment or therapy plans need to be drawn up along with frequent check ins to make sure kidney and liver functions are around normal and insulin therapy are working. If needed, the patient can undergo thyroxin therapy in order to maintain proper thyroid stimulating hormone levels. This has only been needed in a few cases were hypothyroidism was present in the patient.

Nucleoside bypass therapy is an experimental treatment aimed to restore the normal levels of deoxyribonucleotides (dNTPs) in mitochondria.

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.

Reversion of lipodystrophy does not occur after withdrawal of protease inhibitors.

NARP syndrome is not curable. Symptomatic relief is targeted. Antioxidants play a role in improving the oxidative phosphorylation that is otherwise impaired.

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.

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.

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.

In terms of treatment for hyper Igm syndrome there is the use of allogeneic hematopoietic cell transplantation. Additionally anti-microbial therapy, use of granulocyte colony-stimulating factor, immunosuppressants, as well as, other treatments may be needed.

GHRH analogs such as tesamorelin can be used to treat HIV-associated lipodystrophy.

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.

Regular administration of exogenous granulocyte colony-stimulating factor (filgrastim) clinically improves neutrophil counts and immune function and is the mainstay of therapy, although this may increase risk for myelofibrosis and acute myeloid leukemia in the long term.

Over 90% of SCN responds to treatment with granulocyte colony-stimulating factor (filgrastim), which has significantly improved survival.

There is no proven treatment for congenital lactic acidosis. Treatments that are occasionally used or that are under investigation include the ketogenic diet and dichloroacetate. Other treatments aim to relieve symptoms – for example, anticonvulsants may be used to relieve seizures.

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

Diagnosis of cortisone reductase deficiency is done through analysis of cortisol to cortisone metabolite levels in blood samples. As of now, there is no treatment for cortisone reductase deficiency. Shots of cortisol are quickly metabolised into cortisone by the dysregulated 11β-HSD1 enzyme; however, symptoms can be treated. Treatment of hyperandroginism can be done through prescription of antiandrogens. They do so by inhibiting the release of gonadotropin and luteinizing hormone, both hormones in the pituitary, responsible for the production of testosterone.

Management for mitochondrial trifunctional protein deficiency entails the following:

- Avoiding factors that might precipitate condition

- Glucose

- Low fat/high carbohydrate nutrition

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 severity and prognosis vary with the type of mutation involved.

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.

Although no cure currently exists, there is hope in treatment for this class of hereditary diseases with the use of an embryonic mitochondrial transplant.

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.

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.

The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone replacement therapy.

Treatments are often ineffective as it comes back with continued exposure to the sun. Assessment by a dermatologist will help guide treatment. This may include use of a Woods lamp to determine depth of the melasma pigment. Treatments to hasten the fading of the discolored patches include:

- Topical depigmenting agents, such as hydroquinone (HQ) either in over-the-counter (2%) or prescription (4%) strength. HQ is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.

- Tretinoin, an acid that increases skin cell (keratinocyte) turnover. This treatment cannot be used during pregnancy.

- Azelaic acid (20%), thought to decrease the activity of melanocytes.

- Tranexamic acid by mouth has shown to provide rapid and sustained lightening in melasma by decreasing melanogenesis in epidermal melanocytes.

- Cysteamine hydrochloride (5%) over-the-counter. Mechanism of action seems to involve inhibition of melanin synthesis pathway

- Flutamide (1%)

- Chemical peels

- Microdermabrasion to dermabrasion (light to deep)

- Galvanic or ultrasound facials with a combination of a topical crème/gel. Either in an aesthetician's office or as a home massager unit.

- Laser but not IPL (IPL can make the melasma darker)

Evidence-based reviews found that the most effective therapy for melasma includes a combination on topical agents.

In all of these treatments the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc dioxide is preferred over that with only chemical blockers. This is because UV-A, UV-B and visible lights are all capable of stimulating pigment production.

Patients should avoid other precipitants including hormonal triggers.

Cosmetic camouflage can also be used to hide melasma.

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.