SYDNEY, March 20 (Xinhua) -- Australian researchers on Friday said they have uncovered a new neurodegenerative condition in which children suffer developmental regression and severe epilepsy, with the disorder appearing to requiring both parents to be carriers of at least one copy of a defective gene.
The Australian-led study found a variation in a gene that causes the major disorder, which involved patients starting with "normal or mild developmental delay" and the onset of seizures starting within the first year of life. "All had a severe and progressive developmental regression following a seizure," according to a statement from the Murdoch Children's Research Institute medical facility.
The "newly discovered condition was different from other chronic neuroinflammation implicated in other neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease and frontotemporal dementia", according to researcher Sue White.
The disorder, with features suggestive of neuroinflammation, appeared to require two copies of the defective gene, meaning both parents had to be carriers of one altered copy, she said.
"In our study the same gene variant was identified in three children of the same ethnic background," White said.
"While the families do not report that their two families are directly related, they are presumed to be distantly related due to the overlap of their family histories, with common ancestors originating from the same town."
The researchers looked at six children from four families with the gene variant who had a similar degenerative condition, the cause of which was unlocked by genomic testing. Advanced molecular techniques were used to dissect the likely cellular pathway affected by the mutation in the respective NRROS gene, according to the institute. By inserting the gene into cells in the laboratory, the team identified other molecules that the gene interacts with. The molecules are crucial for a number of brain cell functions, including adding the insulating layers around nerve fibers and producing brain immune cells.
The findings were published in The American Journal of Human Genetics.
The research "highlighted the power of new genomic sequencing technologies," according to institute scientist John Christodoulou.
"Now that we know the causative gene, we are in a better position to understand the underlying biology behind the disorder, which we hope in future may translate to targeted treatments specific for the disorder," he said.
