The link between autism and mitochondrial disease is a controversial issue within the autism community. The 2008 Hannah Poling vaccine case linked Poling's autism type symptoms to mitochondrial disease aggravated by vaccines. Experts claim that cases of mitochondrial disease are rare but the condition's possible lack of visible symptoms concerns parents. What is mitochondrial disease and does it have a link to autism?
Mitochondrial Disease Overview
Mitochondrial disease is a group of over 40 different disorders that prevents the proper function of mitochondria inside cells. Mitochondria are a part of every cell in the body and are in charge of efficiently turning sugar and oxygen into energy. When a mitochondrial disease occurs, the mitochondria cannot properly turn sugar and oxygen into energy and the cells have an impaired function. The rare disorder affects both children and adults. According to the United Mitochondrial Disease Foundation, one in 4,000 children develops mitochondrial disease by age ten.
Types of Mitochondrial Disease
Mitochondrial disease types are categorized based upon the affected area of the body. The disease can affect cells in the following parts of the body:
Some people with mitochondrial disease only experience impaired function in one organ, while others have impairments in multiple organs.
Mitochondrial disease is treatable and treatment involves treating sets of symptoms.
Symptoms of Mitochondrial Disease
Every case of mitochondrial disease is different. Some people experience no visible symptoms while others have numerous symptoms. The symptoms of mitochondrial disease include:
- Stunted growth
- Developmental delays
- Learning disabilities
- Visual or hearing difficulties
- Intellectual disability
- Heart disease, liver or kidney disease
- Muscle coordination problems
- Respiratory impairments
- Neurological problems
- Thyroid problems
About Autism and Mitochondrial Disease
Autism and mitochondrial disease are two separate medical conditions. According to the Centers for Disease Control and Prevention, a person with autism may also have mitochondrial disease. Someone with mitochondrial disease may experience autism-like symptoms but not have autism. Mitochondrial disease can also occur without any autism type symptoms. People with mitochondrial disease are at high risk for developing neurological problems such as autism due to the impairments in energy levels. In mitochondrial disease, cells need a higher amount of energy than average. If the cells of the body do not receive enough energy, they can get damaged. The limited amount of energy may result in autism-like symptoms.
Are Mitochondrial Disease and Autism Linked?
Are autism and mitochondrial disease linked? Recent studies suggest that mitochondrial disease may affect more people with autism than neurotypical people. One study, a 2005 Portuguese study in the Developmental Medicine and Child Neurology journal, found that more than 7.2 percent of people with autism have mitochondrial disease. A 2005 Irish study from Trinity College found an association between mitochondrial disease and autism by identifying certain genes. Researchers studied the DNA of 174 affected people and their siblings.
A number of autism experts such as the Cleveland Clinic's Dr. Bruce Cohen and a former president of the Mitochondrial Medicine Society claims that mitochondrial disease is rare among people with autism.
2008 Hannah Poling Case
In 2008, the federal Vaccine Court granted vaccine injury compensation to Hannah Poling, whose pre-existing mitochondrial disease was aggravated by vaccinations, causing autism-like symptoms.
Some experts argue that the Poling does not have autism and that her symptoms only resemble autism and are all a part of the mitochondrial disease. They are quick to point out that this is why the Vaccine Court Special Master called Poling's symptoms autism-like. Yet according to the New England Journal of Medicine, Poling has mild to severe autism symptoms.
Mitochondrial disease and autism share an association. Autism experts disagree over the prevalence of mitochondrial disease and autism. More studies are necessary to discover more about the link between the two disorders and if they share common origins.