Gene discovery set to help with mysterious paralysis of childhood
Alternating hemiplegia of childhood (AHC) is a very rare disorder that causes paralysis that freezes one side of the body and then the other in devastating bouts that arise at unpredictable intervals. Seizures, learning disabilities and difficulty walking are common among patients with this diagnosis.
Researchers at Duke University Medical Center have now discovered that mutations in one gene cause the disease in the majority of patients with a diagnosis of AHC, and because of the root problem they discovered, a treatment may become possible.
The study was published online on July 29 in Nature Genetics.
AHC is almost always a sporadic disease, which means that typically no one else in the family has the disease, said Erin Heinzen, Ph.D., co-author of the study and Assistant Professor of Medicine in the Section of Medical Genetics. "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."
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.
In a remarkably broad international collaborative effort, the authors partnered with three family foundations (USA, Italy and France), including scientists from 13 different countries, to study an additional 95 patients and showed over 75 percent had disease-causing mutations in the gene for ATP1A3.
"This study is an excellent example of how genetic research conducted on a world-wide scale really can make a difference for such a rare disorder as AHC," said Arn van den Maagdenberg, Ph.D., and co-author on the study and geneticist from Leiden University Medical Centre in the Netherlands. "It truly was an effort from many research groups that led to this remarkable discovery."
"This kind of discovery really brings home just what the human genome project and next-generation sequencing have made possible," said David Goldstein, Ph.D., Director of the Duke Center for Human Genome Variation and co-senior author on the study. "For a disease like this one with virtually no large families to study, it would have been very difficult to find the gene before next-generation sequencing."
"Ideally what you want from a study like this is a clear indication of how the mutations change protein function so you know how to screen for drugs that will restore normal function or compensate for the dysfunction," said Goldstein, who is also a Professor in Duke Molecular Genetics and Microbiology. "While there is considerably more work to do, our initial evaluation of the mutations suggests that they may alter the behavior of the transporter pump as opposed to reducing its activity, as do other mutations in the gene that cause a less severe neurological disease."
Co-senior author Mohamad Mikati, M.D., Professor of Pediatrics and of Neurobiology, and Chief of Pediatric Neurology at Duke, said, "Many years ago my work with other collaborators on a family with this disease proved that AHC can be caused by genetic factors, but until now we did not know the underlying gene abnormality.
"The finding that ATP1A3 mutations cause AHC will increase awareness of the disease and the ability to accurately diagnose patients," Mikati said. "While it may take a while for novel drugs to be developed to better treat this disease, we will see an immediate impact through specific testing for mutations in this gene when we suspect a case of AHC. This direct testing will prevent misdiagnoses that too often have caused patients to be treated with inappropriate medications."
Journal reference: Nature Genetics
Provided by Duke University Medical Center
- Sequencing works in clinical setting to help -- finally -- get a diagnosis May 08, 2012 | not rated yet | 0
- Gene discovered for Weaver syndrome Dec 15, 2011 | not rated yet | 0
- Sequencing a single genome yields cause of inherited bone disorder Jun 17, 2010 | not rated yet | 0
- Genetic mutation linked to Parkinson's disease Jul 15, 2011 | not rated yet | 0
- Yeast mimics severity of mutations leading to fatal childhood illness Dec 22, 2008 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
Northwestern University scientists have shown a gene involved in neurodegenerative disease also plays a critical role in the proper function of the circadian clock.
Genetics May 16, 2013 | 3 / 5 (1) | 0 |
Informed consent is the backbone of patient care. Genetic testing has long required patient consent and patients have had a "right not to know" the results. However, as 21st century medicine now begins to use the tools of ...
Genetics May 16, 2013 | 5 / 5 (1) | 3 |
Ethicists provide framework supporting new recommendations on reporting incidental findings in gene sequencing
In a paper published in Science Express, a group of experts led by bioethicists in the Center for Medical Ethics and Health Policy at Baylor College of Medicine provide a framework for the new American College of Medical Geneti ...
Genetics May 16, 2013 | not rated yet | 0
The use of genome-wide analysis (GWA), where the entirety of an individual's DNA is examined to look for the genomic mutations or variants which can cause health problems is a massively useful technology for diagnosing disease. ...
Genetics May 16, 2013 | not rated yet | 0
DNA databases might help identify victims of crime and human trafficking, but how do we safeguard the personal privacy of innocent victims and family members? A new report online May 15 in the Cell Press journal Trends in ...
Genetics May 15, 2013 | not rated yet | 0
Researchers at the University of Wisconsin have identified a potential new risk factor for obstructive sleep apnea: asthma. Using data from the National Institutes of Health (Heart, Lung, and Blood Institute)-funded Wisconsin ...
4 hours ago | not rated yet | 0 |
A new study looking at sleep-disordered breathing (SDB) and markers for Alzheimer's disease (AD) risk in cerebrospinal fluid (CSF) and neuroimaging adds to the growing body of research linking the two.
4 hours ago | 5 / 5 (1) | 0 |
In their quest to learn more about the variability of cells between and within tissues, biomedical scientists have devised tools capable of simultaneously measuring dozens of characteristics of individual ...
5 hours ago | 5 / 5 (1) | 0 |
Scientists at Johns Hopkins have turned their view of osteoarthritis (OA) inside out. Literally. Instead of seeing the painful degenerative disease as a problem primarily of the cartilage that cushions joints, ...
5 hours ago | 5 / 5 (2) | 0 |
Gourmands and foodies everywhere have long recognized ginger as a great way to add a little peppery zing to both sweet and savory dishes; now, a study from researchers at Columbia University shows purified components of the ...
4 hours ago | not rated yet | 0
The hunt for an HIV vaccine has gobbled up $8 billion in the past decade, and the failure of the most recent efficacy trial has delivered yet another setback to 26 years of efforts.
9 hours ago | not rated yet | 0