Mitochondrial disease during infancy and childhood

Abstract Mitochondrial disease has only been genetically defined since the late 1980's, yet the pathophysiology of mitochondrial function and genetics has altered the way we think of disease. Mitochondria have their own DNA and are independent replicating organelles that are bound to the energetic needs of cells. Diseases due to alteration in mitochondrial DNA are inherited exclusively via maternal inheritance. But disease can also be inherited in a Mendelian fashion. The cross-talk between genomes can create a wide variety of diseases by altering mitochondrial function and hence, diminishing the availability of energy for cellular metabolism. As one would expect, the developing infant and/or child would have the greatest dependency on the need for energy to ensure proper development. Indeed, defects in mitochondrial function produce the most common inborn error of metabolism leading to disease. This review will highlight the pathophysiology behind mitochondrial dysfunction as well as describe the most common of the group of mitochondrial diseases found in this age range.