In normal reproduction, mtDNA inheritance is exclusively maternal.
By contrast, a woman with a heteroplasmic mtDNA mutation, may transmit a variable amount of mutated mtDNA to her children.
The first diagnosis of a mitochondrial disorder occurred in 1959, and the genetic material of microchondria, called mtDNA, was discovered in 1963.
Genetic defects may be passed through nuclear DNA (nDNA), the genetic material found in each cell that determines the majority of hereditary characteristics, or through mtDNA.
Maternal inheritance. mtDNA is only passed from mother to child because the mitochondria of a sperm is located in the sperm's tail, which is not involved in conception.