Friday, September 18, 2020
US flag

Mitochondrial DNA mutations linked to autism

Children diagnosed with autism spectrum disorder have greater numbers of harmful mutations in their mitochondrial DNA than family members, report Zhenglong Gu of Cornell University in Ithaca, New York, and colleagues, in a study published yesterday in PLOS Genetics.

Increasingly, studies point to malfunctions in mitochondria—the powerhouses of the cell—as a cause of ASD, but the biological basis for this relationship is unclear.

To see if a genetic link exists between mitochondrial malfunction and ASD, the scientists analyzed mitochondrial DNA sequences from 903 children with ASD, along with their unaffected siblings and mothers. They discovered a unique pattern of heteroplasmic mutations, where both mutant and normal mitochondrial DNA sequences exist in a single cell.

Children with ASD had more than twice as many potentially harmful mutations compared to unaffected siblings, and 1.5 times as many mutations that would alter the resulting protein. The researchers went on to show that these mutations can be inherited from the mother, or the result of spontaneous mutation during development.

The scientists noted that the risk associated with these mutations is most pronounced in children with lower IQ and poor social behavior compared to their unaffected siblings.

Carrying harmful mutations in mitochondrial DNA is also associated with increased risk of neurological and developmental problems among children with ASD. Because mitochondria play a central role in metabolism, these findings may help explain the metabolic disorders commonly associated with ASD and other neurodevelopmental disorders.

Evaluating mutations in the mitochondrial DNA of high-risk families could help improve the diagnosis and treatment of these diseases.

“The result of our study synergizes with recent work on ASD, calling attention to children diagnosed with ASD who have one or more developmental abnormalities or related co-morbid clinical conditions for further testing on mitochondrial DNA and mitochondrial function,” Zhenglong Gu says.

“Since many neurodevelopmental disorders and related childhood disorders show abnormalities that converge upon mitochondrial dysfunction, and may have mtDNA defects as a common harbinger, future research is needed to elucidate the mitochondrial mechanisms underpinning to these diseases.

“Ultimately, understanding the energetic aspects of neurodevelopmental disorders may lead to entirely new kinds of treatments, and preventative strategies that would target mitochondria.”

Paul Katula is the executive editor of the Voxitatis Research Foundation, which publishes this blog. For more information, see the About page.

Recent posts

Students help in wake of Gulf Coast storms

Hurricane victims in the South got some much needed help from students at one Louisiana school. Laura and Sally have been very destructive.

Scientific American endorses a candidate

It's rare that a science journal would endorse a presidential candidate, but it has happened, due mainly to Pres. Trump's rejection of science.

Student news roundup, Maryland, Sept. 16

The pandemic reveals much more about us than our unpreparedness for virtual learning; Md. students look at healthcare and choices about schooling.

Smoke from Calif. paints the East Coast sun

The sunrise this morning in Baltimore and Chicago was cooled by smoke from the Calif. wildfires, which created a thick haze aloft.

Student news roundup, Illinois, Sept. 14

Special ed advocate in Evanston dies; Remembering 9/11; Business, fine arts, and cultural life during the pandemic.

No, the president can’t run for a 3rd term

The 22nd Amendment limits the number of times a president can be elected to two. But maybe Constitutions mean little to the current administration.

Worst Calif. wildfire season in decades

Wildfires in what could be one of Calif.'s worst autumns ever have destroyed structures, including schools, killed people, and mass evacuations.

Children will wait to impress others

Does it pay off to wait for a bigger reward, or should you just take a smaller reward quicker? The "marshmallow test" has some insights.

School opens virtually in most Md. districts

School is now in session across all of Maryland, and it's mostly online, despite calls to keep trying to get in-person instruction.

Student news roundup, Illinois, Sept. 8

The pandemic, performing arts, and politics generally led student news stories from the Prairie State this past week.

On Trump’s ‘losers’ and ‘suckers’ remark

It was hard to swallow when it was reported that the president said military personnel who had died in battle were suckers and losers.