Mitochondrial DNA Causes Drastic Effects On Nuclear DNA

     New research is revealing that subtle changes in mitochondrial function may cause a very broad range of common metabolic and degenerative diseases. Dr. Douglas Wallace is leading the research at The Children's Hospital of Philadelphia. The study has shown that small changes in the ratio of mutant to normal mitochondrial DNA can lead to abrupt changes in the expression of numerous genes within nuclear DNA. These changes also correspond directly with mutations in mitochondrial DNAthat are associated with diabetes, autism, brain disease, muscle disease, heart disease, and lethal infantile disease. 

     Dr. Wallace says, "By showing that subtle changes in the cellular proportion of the same mitochondrial DNA mutation can result in a wide range of different clinical manifestations, these findings challenge the traditional model that a single mutation causes a single disease. The research offers key insights into understanding the underlying cause of metabolic and neurodegenerative disorders such as diabetes, Alzheimer, Parkinson and Huntington disease, as well as human aging. The discrete changes in nuclear gene expression in response to small increases in mitochondrial DNA mutant level are analogous to the phase changes that result from adding heat to ice. As heat is added, the ice abruptly turns to water and with more heat, the water turns abruptly to steam." 
     This means that the quantitative change taking place in mitochondrial DNA is producing qualitative results, since it is coordinating changes in nuclear gene expression. Dr. Wallace has been researching mitochondrial DNA for years, beginning in 1988 when he was the first to demonstrate that mitochondrial DNA mutations can cause human disease. Since then, he has continued studying mechanisms by which mitochondrial DNA contribute to diseases by disrupting the body's energy production. 
     I found this article interesting because it still amazes me that mitochondria have their own DNA and that this DNA can have such a profound impact. The implications of knowing more about how this mitochondrial DNA works and its effects on nuclear DNA could be the step we need to combat many genetic diseases more effectively. 

Article: http://www.medicalnewstoday.com/releases/284346.php