Mito Mightily Disappoints Autism Researchers

DNA-basesBy Amick B.
Research shows a strong genetic basis for autism, but for years scientists have been unable to pinpoint the specific genetic variants associated with the condition, which may affect as many as one in 88 children in the United States.

For some time now researchers have speculated that mitochondrial DNA (mtDNA) may be involved in autism.  Mitochondrial DNA , which is passed down from mother to child, is found in the cell’s mitochondria — distinct structures that act as a power plant for the cells by converting oxygen and simple sugars into readily-usable energy. Scientists have hypothesized that byproducts or problems with this process might be related to the development of autism spectrum disorders.

A recent study, however, suggests that genetic variants in mtDNA may not be as important as some had supposed.  The researchers, led by Athena Hadjixenofontos and Jacob  McCauley from the University of Miami, considered mtDNA from nearly 1300 individuals from various ancestral backgrounds with autism spectrum disorders.  They looked at both associations with mitochondrial haplogroups as well as individual variants within the mtDNA.  In both cases, they came up empty handed. The mito was mightily disappointing.

Although no significant associations resulted from this study, the mitochondrial genome remains an intriguing potential path toward further investigation into the genetics of disorders on the spectrum.  It may be that with larger sample sizes they may find that mtDNA plays an important role in autism genetics after all.  Or, it may be that with further research they will be able to conclusively rule out the role of mtDNA.  Either way, we’ll come closer to understanding this common condition.