Mitochondrial depletion syndrome (MDS) is a group of rare genetic disorders that limit the number of mitochondria inside of cells. Mitochondria are organelles that produce energy for the cell, and a reduction in their number can lead to a variety of symptoms. MDS is a genetically and clinically heterogeneous group of autosomal recessive disorders that are characterized by a severe reduction in mitochondrial DNA. The term "depletion" refers to the markedly decreased amount of mitochondrial DNA found in muscle, liver, and brain tissues in these disorders.
MDS is caused by mutations that may be inherited from the parents or may form spontaneously during the development of the fetus. It is associated with the mutations of mitochondrial genes in the nucleus, and several genes including TK2, FBXL4, are known to be related to MDS. There are different types of MDS, including myopathic MDS, hepatocerebral MDS, and encephalomyopathic MDS, each with its own set of symptoms. Symptoms of MDS can include muscle weakness, intellectual disability, eye problems, and neuropathy. There is currently no curative treatment for any form of MDS, though some preliminary treatments have shown a reduction in symptoms.
