How are mitochondrial disorders typically inherited?

Mitochondrial disorders are primarily inherited through the mother due to the unique nature of mitochondrial DNA. Mitochondria, the energy-producing structures in cells, have their own DNA, which is distinct from the nuclear DNA found in the cell nucleus. During reproduction, mitochondria from the sperm are usually eliminated after fertilization, meaning only the mitochondria contributed by the egg are passed to the offspring.

As a result, any mutations present in the mitochondrial DNA will be passed down from the mother to all her children, regardless of their sex, while the father’s contribution in this respect has no bearing on the mitochondrial DNA of the offspring. This maternal inheritance pattern explains why mitochondrial disorders can be observed and traced through maternal lineage, affecting descendants who receive their mitochondrial DNA solely from their mother.