Primary disorder of muscles Mitochondrial myopathies
Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes (MELAS)
Rare Disease Classifications:
IMPORTANT INFORMATION
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Rare diseases typically display a high level of symptom complexity and variability. Individuals diagnosed with the same rare disease may be impacted differently and each person’s experience is unique. Please seek support from qualified healthcare professionals to learn more about the most suitable care and support options for you.
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Contributors
This page has been co-developed with RVA Partner, Mito Foundation.1
Quick Page Search:
Emergency Management | Clinical Care Guidelines | Synonyms | Summary | Personal Stories | Symptoms | Cause/Inheritance | Diagnosis | Treatment | Clinical Care | Research and Data | Rare Disease Organisation(s) | Support Services/Resources | Mental Health | Other | References
Emergency Management
There may be special considerations for the emergency management of individuals living with MELAS presenting to emergency departments. Relevant specialists should be consulted.
Individuals with MELAS may experience seizures and stroke-like episodes. It is recommended that valproic acid/sodium valproate should not be used for treatment of seizures.2,3
Individuals with MELAS may also have a built up of lactic acid in the blood (lactic acidosis). It is recommended that lactate levels are closely monitored during critical care4 and dichloroacetate should be avoided for treatment as its use has been associated with causing nerve toxicity.2,3
Clinical Care Guidelines
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 for mitochondrial conditions, including MELAS.4
The following guidance is available from international experts outside Australia; however, there may be information that is not relevant or applicable to the Australian context, and may not be up to date:
Consensus-based statements for the management of mitochondrial stroke-like episodes – PMC (nih.gov), published in 2019, represents a group opinion of experts from multiple medical centres in the United Kingdom and Europe on stroke-like episodes associated with MELAS.3
Synonyms
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes
Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes
Summary
MELAS, which stands for Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes, is a mitochondrial disorder.1 This condition affects various parts of the body, in particular the brain and nervous system, and muscles.2,5 Symptoms include, but are not limited to, stroke-like episodes with seizures, headaches, vomiting and encephalopathy, with various neurological features.2-3,5-7 Individuals with MELAS also have a build-up of lactic acid (lactic acidosis), which can result in muscle weakness, fatigue, difficulty breathing, abdominal pain and vomiting.5,7 These symptoms usually present before 40 years of age, most typically in childhood,2 and tends to be progressive.5
MELAS is a genetic condition, which is mainly caused by genetic changes in mitochondrial DNA that results in impaired function of the mitochondria (mitochondrial dysfunction).2,5 As mitochondrial DNA is passed on from mother to child, females with MELAS are also likely to have children with MELAS.5
Personal Stories
MELAS varies between individuals, and each person’s experience is unique.
Please visit Mito Foundation: Mito Stories (MELAS) to read the personal stories of people living with MELAS.
Symptoms
Common features of MELAS include stroke-like episodes, with seizures, headaches, vomiting and encephalopathy.2 Individuals may have hearing impairment, cortical vision loss/blindness due to damage to the part of the brain involved in vision processing, learning disabilities and short stature.2,5-7 Individuals often have increased levels of lactic acid (lactic acidosis) with muscle weakness, fatigue, difficult breathing, abdominal pain and vomiting.5.7 There may also be a decline in cognitive and physical function.6
Further information about symptoms that have been associated with MELAS can be found at Human Phenotype Ontology: MELAS.
Please speak to your medical team to learn more about the symptoms of MELAS.
Cause/Inheritance
MELAS is caused by a genetic change in mitochondrial DNA that result in impaired mitochondrial protein synthesis.2 There have been at least 17 different mitochondrial genes associated with MELAS – specific genetic changes in either of those genes have been found to cause this condition. These genetic changes may occur randomly (de novo mutations that occur during conception or before birth) or are inherited from the mother as mitochondrial DNA is passed down from mothers to their children (maternal inheritance pattern).
More information on maternal/mitochondrial inheritance pattern can be found at Mitochondrial inheritance (NSW Government Health: Centre for Genetics Education).
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 on genetic counselling can be found on the National Services page and specific State and Territory Services pages on the RARE Portal.
Diagnosis
A diagnosis of MELAS may be based on clinical features and findings as well as genetic testing.7
Clinical tests may include brain imaging such as magnetic resonance imaging (MRI) to identify features of the stroke-like episodes, head computed tomography (CT) scans to look for calcium deposits, and magnetic resonance spectroscopy (MRS) to identify presence of increased lactate.2,7
Biochemical analyses may involve measuring levels of lactate in the blood and in the cerebrospinal fluid (CSF; fluid that surrounds the brain and spinal cord), as well as levels of CSF protein.2 Muscle biopsy may also be performed to look for mitochondrial abnormalities, such as the appearance of ragged red fibres.2,7
Information about published clinical diagnostic criteria for MELAS can be found at GeneReviews®: MELAS – Diagnosis.
Genetic testing may be done to identify genetic variants that could be associated with MELAS. The genetic tests are usually performed on blood samples, but additional samples may be required from tissues such as from inner cheek (buccal mucosa), skin, hair, urine or skeletal muscle.2,7
Treatment
There is no curative treatment for MELAS, but there are strategies to manage the symptoms such as the stroke-like episodes, seizures and lactic acidosis.2,3 It is best to speak with your medical team to learn more about any suitable management strategies for symptoms associated with MELAS. A multidisciplinary medical team is usually required.
Contraindications – it is advised that valproic acid/sodium valproate should not be used for treatment of seizures, and dichloroacetate should be avoided for treatment of lactic acidosis as its use has been associated with causing nerve toxicity. 2,3
It is also recommended that individuals with MELAS be regularly evaluated or monitored for issues with vision, hearing, and kidney, heart muscle disease (cardiomyopathy) or heart (cardiac) conduction defects, cognitive abilities and dementia, and diabetes mellitus.2
Clinical Care
Healthcare professionals involved in the treatment of MELAS may include general practitioners (GP), paediatricians, metabolic physicians/consultants, geneticists, cardiologists, neurologists, and ophthalmologists.1,5 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.
Research and Data
Information regarding research and clinical work in the field of primary mitochondrial disease can be found at Research – Mito Foundation. This includes:
- Mito Registry – collects information about Australians with confirmed or suspected mitochondrial disease for the purpose of research into treatments and cures.
- Participate in Clinical Studies – studies relevant to individuals with mitochondrial disease
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.
Please visit Australian Clinical Trials to learn about clinical trials for mitochondrial diseases in Australia; there may not be any clinical trials currently available.
Information regarding clinical trials for mitochondrial diseases in other countries can be found at ClinicalTrials.gov; there may not be any clinical trials currently available.
It is best to discuss your interest in any clinical trials with your medical team to determine suitability and eligibility.
Rare Disease Organisation(s)
Mito Foundation
Website: https://www.mito.org.au/contact/
Phone: 1300 977 180
Email: [email protected] (for general enquiries)
[email protected] (for support enquiries)
The Mito Foundation is the only organisation dedicated to supporting and empowering people affected 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 necessarily monitor or endorse each group/organisation’s operational governance.
Support Services/Resources
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
- Pathways Telehealth Nurse Program – to work with a Pathway Telehealth nurse to develop a tailor-made care plan for support, education and connection with other services
- 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.
Mental Health
Please visit the ‘Mental Health’ sections listed on the National and State Services pages.
Mito Foundation: Psychological Impacts of Mito provides information relevant to the mental wellbeing of individuals with a mitochondrial condition diagnosis.
Other
Further information relating to mitochondrial conditions including MELAS can be found at:
References
- Australian Mitochondrial Disease Foundation Ltd. (Mito Foundation). Accessed 16 January 2024. https://www.mito.org.au/
- El-Hattab AW, Almannai M, Scaglia F. MELAS. 2001. Updated 29 November 2018. In: Adam MP, Mirzaa GM, Pagon RA, et al. GeneReviews® [internet]. Seattle (WA): University of Washington Seattle. 1993–2023. Accessed 31 January 2024. https://www.ncbi.nlm.nih.gov/books/NBK1233
- Ng YS, Bindoff LA, Gorman GS, et al. 2019. Consensus-based statements for the management of mitochondrial stroke-like episodes. Wellcome Open Res. 2019;13(4):201. https://doi.org/10.12688/wellcomeopenres.15599
- Sue CM, Balasubramaniam S, Bratkovic D, et al. Patient care standards for primary mitochondrial disease in Australia: An Australian adaptation of the Mitochondrial Medicine Society recommendations. Intern Med. J. 2021; 52:110-120. https://doi.org/10.1111/imj.15505
- Genetic and Rare Diseases (GARD) Information Center. MELAS. Accessed 31 January 2024. https://rarediseases.info.nih.gov/diseases/7009/melas
- MELAS. Accessed 31 January 2024. https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=550
- National Organization for Rare Disorders (NORD). MELAS Syndrome. Accessed 31 January 2024. https://rarediseases.org/rare-diseases/melas-syndrome/
Page Last Updated
27/08/2024 09:15
