Mitochondrial diseases are a group of genetic and metabolic conditions that affect the mitochondria. Mitochondria are structures in the cells of a person’s body that produces energy.^1,2 When mitochondria are unable to produce sufficient energy for the cells, this can lead to organs not functioning properly, and in some cases organ failure and premature death.^1,2 Mitochondrial diseases are often summarised as “any symptom, in any organ, at any age”,¹ as it can cause a wide range of symptoms, affect almost any body system, and can present at any age.^1,3 Among the tissues and organs that are most commonly affected are the brain and nerves, eyes, ears, heart, muscles, kidneys and liver as well as the digestive and endocrine (hormone-producing) systems.^1,3 Multiple organs can be affected in some individuals, resulting in a multisystemic condition. In addition to the wide range of symptoms, there is high variability in how the symptoms may present and the symptoms can often be mistaken for other illnesses.

A list of specific mitochondrial conditions can be found at RARE Portal: List of Mitochondrial Diseases. Individual pages for primary mitochondrial conditions will be added to the RARE Portal over time.

Synonyms: Mito; MD; Primary mitochondrial disease; mitochondrial myopathy; mitochondrial encephalopathy; mitochondrial cytopathy.

Universal rare disease classifications provide a common language for recording, reporting and monitoring diseases. Please visit the Rare Disease Classifications page for more information about these internationally recognised classifications.

Please refer to the individual mitochondrial diseases for their specific classifications.

There is a wide range of symptoms associated with mitochondrial diseases that can present at any age and various organs can be affected.¹

Information about the various symptoms associated with mitochondrial diseases can be found at Mito Foundation: Understanding symptoms of mito.

Please speak to your medical team to learn more about the symptoms for a specific type of mitochondrial condition.

Rare diseases are often serious and progressive, exhibiting a high degree of symptom complexity, leading to significant disability. Majority of the estimated two million Australians living with a rare disease meet the Australian Government’s definition for disability (in accordance to the Australian Public Service Commission and Australian Bureau of Statistics), and many experience severe and permanent disability impacts. If you or someone you care for is experiencing disability-related impacts from a rare condition, please speak with a health or disability professional for advice. Information about relevant disability support can be found at the RARE Portal’s Disability Support Information page.

Mitochondrial diseases are caused by disease-causing genetic changes (variants) in genes that affect mitochondria in cells. Mitochondria, also known as the powerhouse of cells, are specialised structures (organelles) within the cells that produce energy.⁴ Whilst a person’s DNA is mostly found in an organelle called the nucleus (known as nuclear DNA), there is also DNA in the mitochondria (known as mitochondrial DNA). There are specific genes in both the nuclear and mitochondrial DNA that are responsible for the mitochondria functioning properly.^1,3 Genetic variants in those specific genes can affect normal functioning of the mitochondria and lead to mitochondrial diseases.

Genetic variants that affect the mitochondria can occur randomly (de novo mutations that occur during conception or before birth) or are inherited from one, or both, parents. Each mitochondrial disease has a specific inheritance pattern.¹

If the genetic change occurs in the nuclear DNA, it can be inherited from either or both parents, depending on whether it is an autosomal or X-linked condition, and whether it has a dominant or recessive inheritance pattern.^1,3,5 If the genetic change occurs in mitochondrial DNA, the condition will only be inherited from mothers as mitochondrial DNA is passed down from mothers to their children (maternal inheritance pattern).

Further information about the genetics of mitochondrial diseases can be found at Mito Foundation: Genetics and Mito.

If you would like to learn more about the inheritance and impact of this condition, please ask your doctor for a referral to a genetic counsellor. Genetic counsellors are qualified allied health professionals who can provide information and support regarding genetic conditions and testing. More information about genetic counselling can be found at:

• Information on Genetic Services
• The National and State Services pages underneath the ‘Genetic Counselling’ sections listed

Diagnosis of mitochondrial diseases may be based on the following:⁴

• comprehensive medical history
• blood and urine tests
• electrophysiology studies
• imaging of the brain and other organs
• audiometry and cardiac investigations
• genetic testing, such as whole genome sequencing (WGS), whole mitochondrial genome (mtDNA) analysis and targeted DNA sequencing
• tissue biopsy of the muscle, skin, or liver

The increasing availability and reduced cost of genetic testing is likely to decrease the need for invasive tests (such as biopsies) and increase the number of people diagnosed through genetic testing.⁴

Please speak to your medical team to learn more about the diagnosis pathway for a specific type of mitochondrial condition and whether you meet the criteria for Medicare-funded genetic testing.

There is currently no curative treatment for mitochondrial diseases. Treatment is targeted at managing symptoms (symptomatic management) and involves a multidisciplinary care team.

Patient care standards for primary mitochondrial disease in Australia: an Australian adaptation of the Mitochondrial Medicine Society recommendations was prepared by a working group of medical practitioners, nurses, and allied health professionals, and includes emphasis on clinical management relevant to Australian context.²

Please speak to your medical team to learn more about the possible treatment or management options for your condition. Treatment will depend on an individual’s specific condition and symptoms. It is also important to stay connected to your medical team so that you can be made aware of any upcoming clinical trial opportunities.

Clinical care for rare diseases often involves a multidisciplinary team of medical, care and support professionals. Please note that the information provided here is as a guide and that RVA does not necessarily monitor or endorse specific clinics or health experts.

Healthcare professionals involved in the treatment of mitochondrial diseases are often part of a multidisciplinary team and may include, but are not limited to, general practitioners (GP), paediatricians, metabolic physicians/consultants, geneticists, neurologists, neurogeneticists, ophthalmologists, neuro-ophthalmologists, endocrinologists, cardiologists, gastroenterologists, respiratory and sleep physicians, dietitians, psychologists, physiotherapists, exercise physiologists, occupational therapists and speech therapists. The need for different healthcare professionals may change over a person’s lifetime and extend beyond those listed here.

Please visit Mito Foundation: Find A Health Professional to request access to a directory of health professionals who have experience seeing individuals with mitochondrial disease.

Mito Foundation: Mito Clinics Directory contains information about Australian clinics, listed by state, that are relevant for individuals with mitochondrial disease.

Patient care standards for primary mitochondrial disease in Australia: an Australian adaptation of the Mitochondrial Medicine Society recommendations has been prepared by a working group of medical practitioners, nurses, and allied health professionals, and includes emphasis on clinical management relevant to Australian context.²

Individuals living with rare diseases may have complex medical issues and disabilities, which are not always visible. It is often useful to refer to their medical history as well as personal information such as a medical card, doctor’s letter, or if available, a rare disease passport, for relevant information.

It may be important to consider the following when managing individuals living with mitochondrial diseases at emergency departments/services:

• People with mito, particularly those at risk of acute episodes or recurrent episodic crises, are recommended to and may carry an emergency management plan. This can help to inform healthcare professionals of specific needs (e.g. nutrition, medications, allergies) as well as contraindicated therapies. This plan often include guidelines for managing a critical illness of emergency and the contact details for their mito specialist.

Recommendations for critical care of individuals with mitochondrial diseases can be found at Patient care standards for primary mitochondrial disease in Australia: an Australian adaptation of the Mitochondrial Medicine Society recommendations.

Information regarding research and clinical work in the field of primary mitochondrial disease can be found at Research – Mito Foundation.

Monash University: The MitoHOPE (Healthy Outcomes Pilot and Evaluation) Program is a pilot introduction of mitochondrial donation into Australian clinical practice. Mitochondrial donation is an assisted reproductive technology which can help some women to avoid transmitting mitochondrial disease to their biological children.

There are specific considerations around participating in rare disease research, including clinical trials. It is important to be mindful of issues such as data privacy, research ethics, consent and differences in research regulations between Australia and other countries.

If you are interested in finding clinical trials for your condition, please visit the following websites; however, there may not be any clinical trials available:

• Australian Clinical Trials
• ClinicalTrials.gov

It is best to discuss your interest in any clinical trials with your medical team to determine suitability and eligibility.

Please note that RVA does not necessarily monitor or endorse each group/organisation’s operational governance and activities.

Australian Organisation:

Mito Foundation
Website: https://www.mito.org.au/contact/

The Mito Foundation is the only organisation dedicated to supporting and empowering people impacted by mitochondrial disease (mito) in Australia. It provides resources and support services for people impacted by mito, and their families, while increasing awareness and understanding of this devastating disease. The foundation aims to transform outcomes for the mito community by driving meaningful change and funding essential research into the prevention, diagnosis, treatment and cures of mitochondrial disorders.

Please note that RVA does not monitor or endorse each group/organisation’s operational governance and activities. When engaging with a group, please consider the information on the RARE Portal’s Finding Helpful Peer and Community Supports page.

Mitochondrial diseases vary between individuals, and each person’s experience is unique.

Please visit Mito Foundation: Mito Stories to read the personal stories of people living with mitochondrial diseases.

If you would like to share your personal story with RVA, please visit the Rare Voices Australia: Share Your Story page. RVA will consider your story for publishing on our website and inclusion on the RARE Portal.

Please visit Mito Foundation: MitoHub for people impacted by mitochondrial diseases. Support services provided by Mito Foundation include:

• Helpline – to talk to a support officer for general advice, assistance in seeking a referral or more information on Mito Foundation support services
• NDIS Navigation Service – to access education, resources and one-on-one guidance to NDIS supports and services through working with a NDIS navigator
• Peer Support – to connect with another person impacted by mito
• Mito Connect Events – to join an upcoming event to find out more about mito

For information on available government and social services that provide support for individuals with a rare disease, please visit the National and State Services pages.

People living with a rare disease, including families and carers, often face unique challenges such as diagnostic delays, misdiagnoses, limited treatment options, and limited access to rare disease specialists and support. These challenges may impact people’s emotional wellbeing and quality of life. Many people find it helpful to seek mental health and wellbeing support to cope with ongoing stress and uncertainty. Connecting with people who have shared experiences through a support group may also be helpful. Information about relevant mental health and wellbeing support can be found at:

• Mental Health and Wellbeing Support for Australians Living with a Rare Disease
• The National and State Services pages underneath the ‘Mental Health’ sections listed

Mito Foundation: Mental health support has information relevant to the mental wellbeing of individuals with a mitochondrial condition diagnosis.

Further information related to mitochondrial diseases can be found at:

• Mito Foundation: MitoHub
• Australian Government – Mitochondrial donation
• Genetic and Rare Diseases (GARD) Information Center: Mitochondrial genetic disorders

• Mito Foundation: For Health Professionals
• Mito Foundation: Maybe It’s Mito (for GPs)
• Mito Foundation: Health Professionals Continuing Professional Education
• GeneReviews®: Primary Mitochondrial Disorders Overview
• Orphanet: Mitochondrial disease

This page has been co-developed by Rare Voices Australia (RVA)’s RARE Portal team in consultation with Mito Foundation.

If you are aware of any additional information that may benefit stakeholders with an interest in this page, or if you notice any broken links or inaccurate information, please let us know via the Contribute page.