Mitochrondrial disease is a disorder of the cells. It can be present from birth, or occur later in life. It can have no symptoms, or create a wide range of physical problems including muscular weakness, developmental delays and heart problems. Mitochondrial disease occurs in fewer than 1:2500-4000 births.
Mitochondrial disease is rare. But according to at least one Portuguese study, it may also be the case that mitochondrial disease is more prevalent among people with autism than it is in the general population. In fact, if this small study is replicated, researchers may find that as much as 5% of the autistic population also has mitochondrial disease. A study by the father of the child who received the Vaccine Court settlement supports the possibility that a significant percentage people with autism may have mitochondria-related metabolic problems.
Interestingly, while the Vaccine Court awarded damages without even going to trial, a statement from the United Mitochondrial Disease Foundation says that there has been no research to date on any relationship between mitochondrial disease and vaccines. On the other hand, Geraldine Dawson, the Chief Science Officer at Autism Speaks (the largest autism-related non-profit in the world) says: "Vaccines stimulate the immune system, which may put stress on the cell function of a child who has asymptomatic mitochondrial dysfunction or disorder such that the child now shows increased symptoms. In an extreme case, the symptoms could involve regression and symptoms of autism."
Mitochondrial disease can have no symptoms, which means it can be invisible to parents -- and even to pediatricians. Mitochondrial disorders may be inherited. But since many cases are inherited through recessive genes, the problem may not be obvious in an affected child's parents. Bottom line: It can be impossible to know whether mitochondrial problems exist without testing.
Given this settlement, and new and existing research, it would seem reasonable for parents with particular concerns (a history of autism or mitochondrial disorders in the family, for example) to ask that their child be tested for mitochondrial disease or disorder before giving vaccines. Unfortunately, there is no simple test for mitochondrial disease, and unless there is some specific reason to suspect it, it may be difficult to get insurance to underwrite the cost of complex evaluations. The Mitochondrial Medicine Society does provide diagnostic information, though, which may be useful to parents as they discuss this issue with their pediatrician.
Source: Lerman-Sagie T, Leshinsky-Silver E, Watemberg N, Lev D. Should autistic children be evaluated for mitochondrial disorders? J Child Neurol. 2004 May;19(5):379-81. Lombard J. Autism: a mitochondrial disorder? Med Hypotheses. 1998 Jun;50(6):497-500.
Oliveira G, Diogo L, Grazina M, Garcia P, Ataíde A, Marques C, Miguel T, Borges L, Vicente AM. Mitochondrial dysfunction in autism spectrum disorders: a population-based study.Dev Med Child Neurol. 2005 Mar;47(3):148.
Poling JS, Frye RE, Shoffner J, Zimmerman AW. Developmental regression and mitochondrial dysfunction in a child with autism. J Child Neurol. 2006 Feb;21(2):170-2.
Pons R, Andreu AL, Checcarelli N, Vilà MR, Engelstad K, Sue CM, Shungu D, Haggerty R, de Vivo DC, DiMauro S. Mitochondrial DNA abnormalities and autistic spectrum disorders. J Pediatr. 2004 Jan;144(1):81-5.
Tsao CY, Mendell JR. Autistic disorder in 2 children with mitochondrial disorders. J Child Neurol. 2007 Sep;22(9):1121-3.