A rare childhood disease may hold clues to treating Alzheimer's and Parkinson's, a study has found.
Scientists analysing A-T disease, which leaves youngsters unable to walk by adolescence, have found new ways of understanding the more common neurodegenerative diseases, according to the report in the online journal Nature Neuroscience.
Children born with A-T have mutations in both of their copies of the ATM gene and cannot make normal ATM protein, and experts at Rutgers University in New Jersey in the US hope their research will lead to new therapies for Alzheimer's and Parkinson's.
The rare genetic childhood disorder - which occurs in about one in 40,000 births - leads to problems in movement, co-ordination, equilibrium and muscle control as well as a number of other deficiencies outside the nervous system.
Using mouse and human brain tissue studies, the researchers from Rutgers found that without ATM, the levels of a regulatory protein known as EZH2 go up.
Looking through the characteristics of A-T disease in cells in tissue culture and in brain samples from both humans and mice with ATM mutation, they found that the increase in EZH2 was a major contributing factor to the neuromuscular problems caused by A-T.
Story continues below the slideshow:
Professor Ronald Hart, from the department of cell biology and neuroscience, said: "We hope that this work will lead to new therapies to prevent symptoms in those with A-T disease.
"But, on a larger level, this research provides a strong clue toward understanding more common neurodegenerative disorders that may use similar pathways. It is a theme that has not yet been examined."
In an additional discovery, Cardiff University scientists have uncovered 11 new genes which are linked to Alzheimer's disease.
Using data from almost 75,000 people across 15 countries, the breakthrough report by an international team of researchers has been published in the Nature Genetics journal.
Jointly led by Cardiff University, the study was the largest of its kind and experts believe it will significantly advance scientists' knowledge of Alzheimer's by throwing open new research avenues and enabling a better understanding of the disease's disordered functional processes.
The work by the International Genomics Project (IGAP) details 11 new regions of the genome involved in the onset of the neurodegenerative condition.
Part-funded by the Medical Research Council, the Welsh Government and Alzheimer's Research UK, the research builds on the genome-wide association analysis study that has since 2009 discovered 10 genes known to be associated with Alzheimer's.
Professor Julie Williams, the head of neurodegeneration at the Cardiff University School of Medicine's Medical Research Council (MRC) Centre on Neuropsychiatric Genetics and Genomics, led one of four global research groups.
She said: "This discovery will pinpoint new mechanisms underlying Alzheimer's disease.
"By combining the expertise and resources of geneticists across the globe, we have been able to overcome our natural competitive instincts to achieve a real breakthrough in identifying the genetic architecture that significantly contributes to our mapping of the disease.
"What surprised us most about the findings was the very strong pattern that showed several genes implicating the body's immune response in causing dementia."
She added: "We now have a total of 21 published genes known to increase the risk of developing Alzheimer's, though a large portion of the genetic risk for the disease remains unexplained. Further research is still needed to locate the other genes involved before we can get a complete picture."
Since February 2011, the leaders of the four largest international research consortia on the genetics of Alzheimer's have joined forces to accelerate the discovery of new genes, and in less than three years, the IGAP scientists have been able to identify more susceptibility genes than was achieved in the last 20 years.
Prof Williams said the next phase of the research focus on people with early onset Alzheimer's - people aged in their 40s and 50s afflicted with more severe forms of the condition.
She added: "Our work demonstrates that given the complexity of such a disease, only a global collaboration will quickly find solutions to tackle this major threat. It would be greatly encouraging to also see the world's molecular biologists all pulling together, breaking out of their silos and uniting in their aim of unravelling disease and developing the treatments to tackle it."
The paper is called Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease.