Mitochondrial disorders: Characteristics and signs
Mitochondrial diseases are a group of genetic conditions that can affect nearly all parts of the body, leading to a wide range of symptoms. These diseases are caused by errors or mutations in DNA, which can occur both inherited and randomly, even in individuals with no family history of the condition.
The diseases are progressive and can worsen over time, causing symptoms such as muscle weakness, exercise intolerance, fatigue, and neurological problems like seizures, headaches, and strokes or stroke-like episodes. Other common symptoms include recurrent vomiting, loss of appetite, and lactic acidosis causing nausea and breathing difficulties.
In children, mitochondrial diseases often appear after a period of normal development, causing coordination difficulties (ataxia), intellectual disability, and recurrent neurological episodes. Adults, on the other hand, may experience progressive neurological decline, cardiomyopathy, hearing loss, and coordination problems like ataxia.
Muscle-related symptoms, such as weakness, exercise intolerance, fatigue, muscle pain, and myopathy, are common across ages. Neurological symptoms, like seizures, stroke-like episodes (especially in MELAS syndrome), headaches, encephalopathy (brain dysfunction), and episodic vomiting, are frequent. Lactic acidosis, which causes symptoms like nausea, vomiting, abdominal pain, fatigue, and rapid breathing, affects multiple systems.
Other systemic symptoms, such as hearing loss, cardiac problems, kidney issues, diabetes, hormonal imbalances, and peripheral neuropathy, are common in both adults and children with mitochondrial disorders.
Diagnosis of mitochondrial diseases can be challenging due to symptoms that are also symptoms of other conditions. However, tests such as exercise testing, cognitive testing, vision and hearing tests, muscle biopsies, blood lactate and pyruvate levels tests, and genetic testing can be used to diagnose the disease.
No specific treatment for mitochondrial diseases exists, but ongoing research is being conducted to manage symptoms and improve the quality of life for people with the disease. Some supplements, such as coenzyme 10, carnitine, and creatine, have shown to be helpful for some people with mitochondrial disease, but there is no evidence to suggest that supplements are helpful for everyone.
People with mitochondrial disease are at greater risk of heart disease and respiratory problems, which can be causes of death for people with the disease. Mitochondrial diseases can lead to complications such as heart damage, breathing problems, and growth and development issues in children.
Life expectancy for people with mitochondrial disease varies and is influenced by the specific diagnosis and severity of symptoms. The disease can also cause dementia in some individuals.
It is important for people with mitochondrial disease to have regular eye exams and hearing tests, as well as care from a multidisciplinary team, including cardiologists, neurologists, and audiologists.
References:
[1] Mitochondrial Medicine Society. (2021). Mitochondrial Diseases. Retrieved from https://www.mitoinfo.org/diseases
[2] National Institute of Neurological Disorders and Stroke. (2021). Mitochondrial Diseases Fact Sheet. Retrieved from https://www.ninds.nih.gov/Disorders/All-Disorders/Mitochondrial-Diseases-Information-Page
[3] United Mitochondrial Disease Foundation. (2021). Mitochondrial Disease Basics. Retrieved from https://www.umdf.org/learn/about-mitochondrial-disease/basics
[4] Mayo Clinic. (2021). Mitochondrial disease. Retrieved from https://www.mayoclinic.org/diseases-conditions/mitochondrial-disease/symptoms-causes/syc-20354413
[5] Genetic and Rare Diseases Information Center. (2021). Mitochondrial Disease Information Page. Retrieved from https://rarediseases.info.nih.gov/diseases/10981/mitochondrial-disease
Genetics and other genetics are crucial in understanding mitochondrial diseases, as these conditions are primarily caused by errors or mutations in DNA. The study of these diseases falls under the realm of science and medicine, as they can lead to a multitude of chronic diseases and health-and-wellness issues, including neurodegenerative disorders such as Alzheimer's, Parkinson's, and other neurological disorders. This group of genetic conditions can result in medical-conditions like heart diseases, respiratory problems, and growth-development issues, particularly in children. Ongoing research is striving to develop treatments and management strategies to improve the quality of life for those affected by mitochondrial diseases.
