text: Acquired conditions in which mitochondrial dysfunction has been involved are:
  * diabetes
  * Huntington's disease
  * cancer
  * Alzheimer's disease,
  * Parkinson's disease
  * bipolar disorder, schizophrenia, aging and senescence, anxiety disorders
  * cardiovascular disease
  * sarcopenia
  * chronic fatigue syndrome
  * ALS
  The body, and each mutation, is modulated by other genome variants; the mutation that in one individual may cause liver disease might in another person cause a brain disorder. The severity of the specific defect may also be great or small. Some defects include exercise intolerance. Defects often affect the operation of the mitochondria and multiple tissues more severely, leading to multi-system diseases.
  It has also been reported that drug tolerant cancer cells have an increased number and size of mitochondria, which suggested an increase in mitochondrial biogenesis. Interestingly, a recent study in Nature Nanotechnology has reported that cancer cells can hijack the mitochondria from immune cells via physical tunneling nanotubes.
  As a rule, mitochondrial diseases are worse when the defective mitochondria are present in the muscles, cerebrum, or nerves, because these cells use more energy than most other cells in the body.
  Although mitochondrial diseases vary greatly in presentation from person to person, several major clinical categories of these conditions have been defined, based on the most common phenotypic features, symptoms, and signs associated with the particular mutations that tend to cause them.
  An outstanding question and area of research is whether ATP depletion or reactive oxygen species are in fact responsible for the observed phenotypic consequences.
  Cerebellar atrophy or hypoplasia has sometimes been reported to be associated.