Researchers at Duke University Medical Center found that mutations in one gene that encoded ATP1A3 caused the disease in the majority of patients.
All of the mutations were found in a gene that encodes ATP1A3, one piece of a key transporter molecule that normally would move sodium and potassium ions across a channel between neurons (nerve cells) to regulate brain activity.
"Knowing that we were looking for genetic mutations in children with this disease that were absent in the healthy parents, we carefully compared the genomes of seven AHC patients and their unaffected parents. When we found new mutations in all seven children in the same gene we knew we had found the cause of this disease," Erin Heinzen, co-author of the study and Assistant Professor of Medicine in the Section of Medical Genetics, said in a statement.
The study was published in journal Nature Genetics.
The research included scientists from 13 different countries, to study an additional 95 patients and it showed that over 75 per cent had disease-causing mutations in the gene for ATP1A3.