Mitochondrial Misconceptions

We had a call from someone under the impression that only women can get a mitochondrial disease . Perhaps the caller’s mistaken idea arose from the fact that mitochondria are inherited solely from the mother. If the particular type of mitochondrial disease results from a fault in mitochondrial DNA (mtDNA) then it can only be inherited from mothers but both sons and daughters have an equal chance of inheriting. The difference is that the daughter can pass the disease onto her children but the son cannot pass it onto his.

However not all mitochondrial disease results from flaws in mtDNA. The mitochondria operate in a complex interrelationship with the main cell nucleus. Some forms result from flaws in the DNA in the main cell nucleus and, in these cases, the inheritance pattern is the same as in other inherited genetic illnesses. A defect can be inherited from either parent or ,in some cases, it takes the genetic defects from both parents in order for symptoms to show in the offspring.

The whole area of mitochondrial genetic inheritance and the manifestation of symptoms is very complex . It is important not to jump to conclusions or make false comparisons with other conditions or other people’s conditions even if these are also mitochondrial. Check all information with your specialist!

We have contact families in which parent and child both have a mitochondrial condition. We have families where a parent only has a mitochondrial condition and children , past the age at which it manifested in the parent, showing no evidence of it. We have families where siblings have the same condition. However we also have many families where only one member seems affected. One of our contacts is a twin. He manifests a mitochondrial condition. His twin brother does not.