Note to Lafora Parents - From the Doctors

Parents, We would like to make sure that all patients have had their data recorded in our central files and that we are aware of your child's mutation information. If you are not sure your child’s Athena lab results are in Dr. Berge Minassian’s database at The Hospital for Sick Children in Toronto please email: Julie Turnbull at jturnbull@sickkids.ca   In the subject line or body of the email, please mention that you are sending us your mutation information from the chelseashope.org website. Thank you, The Lafora Research Team

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Research Articles

Info from Dr. Escueta

May 2011: Exciting Possible Scientific Breakthrough from Dr. Berge Minassian
The article is certainly the most positive to date about controlling LD. Some of you might remember him mentioning at our annual fundraising of a possible good result in one animal, that needed confirmation. IT WORKED! In the simplest form and to the best of a parent's understanding, the article says that by inhibiting PTG (protein targeting glycogen synthase), the glycogen concentrations in the brain are reduced (but not completely eliminated) and, most importantly, a dramatic reduction of the production of Lafora bodies occurs in brain, liver, and the skeleton muscle. . . .read more

March 2, 2011 - Article: Glycogen Synthase: An Old Enzyme with a New Trick

Phosphorylation of glycogen has been known for decades; however, the basic metabolic pathways responsible for this modification are unknown. In this issue, Tagliabracci et al. (2011) report the enzyme responsible for incorporating phosphate and the chemical nature of the phosphate linkage, providing a framework for expanding our understanding of a devastating form of epilepsy. read more

March 2, 2011 - Article: Phosphate Incorporation during Glycogen Synthesis and Lafora Disease

Glycogen is a branched polymer of glucose that serves as an energy store. Phosphate, a trace constituent of glycogen, has profound effects on glycogen structure, and phosphate hyperaccumulation is linked to Lafora disease, a fatal progressive myoclonus epilepsy that can be caused by mutations of laforin, a glycogen phosphatase. read more

April 28, 2011 - Article: PTG Depletion Removes Lafora Bodies and Rescues the Fatal Epilepsy of Lafora Disease

Lafora disease is the most common teenage-onset neurodegenerative disesase, the main teenage-onset form of progressive myclonus epilepsy (PME), and one of the severest epilepsies. Pathologically, a starch-like compound, polyglucosan, accumulates in neuronal cell bodies and overtakes neuronal small processes, mainly dendrites. read more

June 2010

Research Update from Dr. Escueta
Dr. Antonio Delgado-Escueta's team continues to maintain the Lafora disease mouse colony at the VA Medical Center in West Los Angeles. This mouse model continues to be used to improve our understanding of the disease mechanisms of Lafora epilepsy and can also be used for drug trials and gene replacement therapy. . .read more

September 2009

We have two aims in our lab. 1) Understanding how Lafora bodies form. 2) Finding a way to get rid of them.
When you look in the brain of a patient who dies of Lafora disease, you see in the vast majority of synapses (the place where one neuron (brain cell) talks to another) these ugly accumulations of starch-like compounds (polyglucosans/Lafora bodies). When one just looks at these images under the electron microscope, one need not be any sort of expert to realize that these synapses cannot be working normally when they are so occupied by these massive structures. Also, these bodies increase over time. The younger the child, the less of them there are and the smaller they are. This is the reason why the disease starts after a certain time, 15 or so years, and why it continues to worsen over time. Everything else you hear or read about this disease, unrelated to Lafora bodies, is meaningless. After all, laforin is a protein that tightly binds polysaccharide and is very difficult to disengage from sugars, and hence its role must be related to the metabolism of polysaccharides.

So, our longer-term aim is to understand how these abnormal polyglucosans form and accumulate. You understand that had this kid of work been done in the decades prior to when Chelsea got sick (and it was not done simply because in those decades we were looking for the genes, an essential component of any research on a genetic disease), then we would have had knowledge that would certainly have allowed us to have a cure. Without knowing the cause and the process of a problem, it is very hard if not impossible to solve a problem. Therefore, we owe it to the children who are currently in the process of becoming Lafora teenagers, to work towards understanding this disease, so that when they are sick, we can cure them.

We are making great strides in the above aim, including most importantly, our recent discoveries in collaboration with Dr. Roach's group, that glycogen has phosphorus on it, and that the amount of this phosphate is what makes normal glycogen normal, or go awry and become polyglucosans. We are now following up this crucial insight and figuring out its details. We hope that when we know more precisely what is going on, we will know precisely where and how to intervene.

But what about the currently sick children with Lafora? What can we do for them? One idea is to replace normal laforin or malin into their brains, as the case may be, and see if that will reverse the problem. It is possible that this will work. But there are major problems with this. Firstly, remember that Lafora disease is only one of countless and much more common brain diseases. There is a world of scientists out there trying to get missing genes into human brains. It is a massive technical challenge, not only to get the gene in, but to make it so that it will not be gotten rid of by the host brain that sees it as foreign, and to make it express just the right amount of protein at just the right times, and in a continuous fashion over the life of the patient. No one has been able to achieve this yet. It will be achieved sometime in the future, but it is relatively unrealistic that we can do what huge groups working on huge diseases have not been able to do. Nonetheless, there is no harm in trying. The other problem with gene therapy is that in my own estimation, I do not see that replacing laforin can get rid of the ALREADY accumulated polyglucosans. My impression of the disease is that laforin's role is the prevention of their formation, not their degradation. To date, there is no publication that shows that replacing laforin in a mouse with Lafora, for example, gets rid of the Lafora bodies. Secondly, what about the malin patients? Replacing laforin cannot help them.

Then, there is the option of correcting stop codons in certain patients who have this particular type of mutation. This is akin to replacing laforin, and again, I have my doubts that this will get rid of the Lafora bodies, but I am obviously not sure, it may well work, though I don't see it that way. Again, this approach applies only to a fraction of the patients who have stop mutations. It does not work for the other patients.

The only way known, and proven, to get rid of starch/polyglucosans, is to digest them with amylase, an enzyme humans, including Lafora patients, make everyday in their saliva. If we could make brain cells make amylase even for a few minutes or hours, it would get rid of the 20-year worth of polyglucosans accumulated. So, our second research aim is find ways to introduce amylase into the brain for a very short time. If we can do this, we could get rid of the Lafora bodies and restore the patient to health. We face the same problem of getting a protein into the brain, but in our case, we need to get it in extremely transiently. Also, this method would work for any Lafora patient, laforin, malin, and all the many types of mutations.

In summary: 1) we want to KNOW Lafora disease, in order to conquer it. 2) meanwhile, we are trying to use a Trojan horse approach to see if we can sneak an army in there through the back door to get rid of the Lafra bodies.

Best,
Berge

January 4, 2009

Dr. Antonio V. Delgado-Escueta and his team are developing two treatment approaches, including 1) gene therapy for all Lafora disease patients, and 2) gentamicin treatment for those patients with nonsense mutations.

1) Gene therapy
The stellate electroencephalography (EEG) machine arrived on November 19, 2008, and the team started EEG recordings on mice the same afternoon. With the new EEG machine, Dr. Escueta now has the capability to monitor the effects of gene therapy on seizures and epileptic form discharges. Expenses include supplies for the EEG machine, a new stereotactic apparatus to measure exact electrode placement, and monthly costs for the mice colony.

Dr. Escueta is now prepared to hire a scientist focused on the gene therapy approach who is trained in mice research models as well as molecular biology. The annual salary for such a researcher is $80,000 a year.

2) Gentamicin treatment
Dr. Escueta and his team have now organized a team of five specialists to execute the protocol. In addition, Dr. Escueta has secured a bio-safety team with three members to oversee the project. We have asked Dr. Paul Beringer, a pharmacokinetics/pharmacologist specialist from the University of Southern California, to participate as a co-investigator. He will be the newest member of the team. Dr. Beringer has extensive experience with gentamicin treatment for cystic fibrosis.

Future funding will be used to absorb a portion of the salaries for the treatment team and safety/oversight committee members. Funding also will support the costs associated with patient treatment, both inpatient and outpatient at the General Clinical Research Center (UCLA-GCRC) where the gentamicin will be administered.

Another Research Perspective

The problem facing a Lafora patient is the conversion in brain cells of normal glycogen, a soluble sugar, into a starch-like insoluble sugar. This insoluble compound accumulates in the brain cells and devastates their function. How and why this happened was a great mystery until recently. We have now discovered that the problem is that normal glycogen in the Lafora patients acquires excessive phosphate, and that it is this phosphate that distorts normal glycogen and makes it become starch-like and insoluble. We now are trying very hard to uncover where this excess phosphate comes from, and then we will try to prevent this, or find ways to remove it so as to re-normalize the glycogen and keep it from precipitating and accumulating. If we can do this, we can treat or cure our patients. How long the way is from this point towards a treatment we do not know, but we now know we are on the right track”.

--Dr. Minassian

 

Words From One of Our Researchers

We essentially breathe, sleep, dream and ceaselessly work on this disease. Our hope is to understand it so fully that we can come up with a treatment. My personal dream is this: Next time a Matt or a Jessica or an Amanda is brought to a neurologist, and the diagnosis of Lafora is made, the doctor would simply write a prescription and say: you have Lafora, take this, all will be alright.

Based on the genes, we have found the proteins disturbed in this disease and we are now painstakingly finding all the interacting proteins and step by step reconstructing the biochemical pathway that is disturbed. We are certain that with understanding will come insights into the cure.

Lafora patients form Lafora bodies in their brain cells, which cause the horrible epilepsy these patients suffer from. In parallel to unraveling the disease processes that lead to Lafora body formation, we are designing a method to remove them from the brain, and return the patient to normalcy. We know that amylase, the starch-digesting enzyme in saliva, can digest Lafora bodies. We are working on a method to introduce amylase into neurons to melt the Lafora bodies away and cure our patients.

The hurdles are many and the work is large, but so is our commitment. The disease is rare, and hard to find government funding for. We therefore count on you.

- Berge Minassian, MD.

Research Overview
Lafora Disease receives practically no funding from the Federal Government or other organizations due to its limited occurrence in the United States. The disease is classified by the Federal Government as an "orphan disease," thus being ineligible for funding available to more prevalent diseases. Fortunately, rapid advances in the biochemistry of glycogen metabolism have occurred stimulated by the discovery of the disease causing genes EPM2A (Laforin) and EPM2B (Malin). These advances have set the stage for the development of treatment protocols and the development of assays to monitor such treatment protocols.

We seek to raise money through contributions to help fund research about these specific treatment protocols and monitoring assays. Please visit the subpages of the research section to learn more about what is going on in Lafora Disease research and to learn more about what we need to do to help combat this disease.

RESEARCH DEVELOPMENTS -- The Lafora Disease Story So Far

MYSTERIES OF BRAIN METABOLISM AND LAFORA DISEASE
One of the mysteries of brain metabolism and for that matter Lafora Disease is why normal nerve cells do not store glycogen. Glucose is the main source of energy in the brain as in other cells and glycogen is the main storage for glucose. Hence glycogen is a source for chronic energy and yet glycogen is not present in normal nerve cells. In contrast, in Lafora Disease, a progressive and deadly form of epilepsy, excessive amounts of abnormally branched glycogen accumulate in toxic amounts and kill nerve cells. This suggested that there must be finely-tuned machinery in the brain that prevents glycogen from appearing much less accumulating in normal nerve cells. This mystery is rapidly being solved by expert biochemists in glycogen metabolism and protein phosphatases spurred on by the discoveries of the disease causing genes in Lafora Disease by clinician scientists. This separate group of scientists has worked furiously, independently but harmoniously, in the last 12 years. In spring of 2007, these scientists met for a Workshop in Sarlat, France, stimulating collaborations, speeding up research, triggering a spate of publications and helping set up the stage for treatment protocols in Lafora Disease.

Finding the Disease Causing Gene of Lafora Disease
The modern story of Lafora Disease started in 1995 in the Epilepsy Genetics/Genomics Laboratories at the Epilepsy Center of Excellence of the Greater Los Angeles VA Medical Center and the David Geffen School of Medicine at UCLA. There, the first chromosome locus (6p24) for Lafora Disease was discovered. This led to the eventual identification of EPM2A (Laforin) in 1998 and EPM2B (Malin) in 2003 by the Los Angeles scientists and previous PhD and postdoctoral students who had then branched out into their own independent laboratories in Toronto (Canada), Madrid (Spain) and Kanpur (India). The families being studied by the Lafora Disease researchers then showed that Laforin belonged to a group of enzymes called dual specificity phosphatases that targeted glycogen while Malin was an E3 ubiquitin ligase, an enzyme involved in the cell disposal unit (like the garbage disposal of a kitchen). By 2002, two mice models of lafora disease were made -- one where the laforin gene was knocked out in the developing embryo was made by collaboration between Los Angeles and Japanese scientists. Another, where a mutation of laforin was inserted in the developing embryo was prepared by Toronto scientists.

Setting the Stage for Laforin Gene Replacement Treatment
Enter the scientist experts on protein phosphatases and glycogen metabolism. First to help in 2005, was the protein phosphatase lab at UC San Diego which showed that EPM2B/malin actually tagged EPM2A/Laforin with a marker (ubiquitin) and set it on its way to the cell disposal unit. In the ensuing two years, the same group of scientists from UC San Diego and Norwich, UK, together with plant biologists in Austria, discovered the counterpart of Laforin in plant and other organisms and showed that humans and other organisms share the common function of laforin in purging excessive carbohydrates and glycogen and preventing glycogen buildup that is harmful to the plant and organism cells. Next came the experts on glycogen metabolism. In 2007, a consortium of scientists from Madrid, Barcelona and Valencia, confirmed by the same UC San Diego team, showed that a complex of Laforin and Malin acting together suppresses the enzyme machinery that makes glycogen in nerve cells. The same complex of Laforin and Malin also sets up for the cell disposal unit the Laforin docking regions for protein phosphatase-1 and glycogen synthase (enzymes necessary for making glycogen). This way, the Laforin-Malin complex ensures suppression and blockade of glycogen formation in nerve cells as well as elimination of glycogen and its necessary enzymes by the cell disposal unit. When nature places a mutation in either Laforin or Malin, not only is poorly branched glycogen formed in excess but elimination through the cell disposal unit of glycogen and its components and its control systems by the Laforin/Malin complex is also dysfunctional and nerve cells die.
Also in 2007, both UC San Diego scientists and Indiana University scientists independently demonstrated that Laforin could release phosphate from amylopectin, a plant carbohydrate similar to glycogen and actual mammalian glycogen. This is very important because it shows for the first time that glycogen like amylopectin is a substrate of Laforin. If Laforin acts as a glycogen phosphatase in vivo, then the phosphate content in glycogen would be elevated in Lafora Disease. This is what is found in the mice whose Laforin has been knocked out. Glycogen phosphatase assay could, thus, provide a way of monitoring treatment.

Blood Brain Barrier Experts in the Epilepsy Center of Excellence at Los Angeles
As the functions of Laforin and Malin were unraveling, so the mysteries of glycogen metabolism were being demystified. Meanwhile, a team of experts on the blood-brain barrier in Los Angeles started to devise a method to deliver Laforin from the blood through the blood-brain barrier into brain nerve cells of mice with Lafora Disease. If the function of Laforin is to purge glycogen from nerve cells, then delivering Laforin into the brain of Lafora Disease patients would clear the brain of Lafora inclusion bodies. Starting in 2002, these scientists in Los Angeles labored through the details of placing Laforin inside a vehicle that should be harmless to humans, namely, pegylated immunoliposomes. (Placing Laforin inside lipids contrasts to placing the gene inside adenoviruses which have now been suspected to cause death in 2 persons and possible leukemia in 2 children.) By 2006, Laforin delivered by immunoliposomes into brains of mice with Lafora Disease was shown to indeed purge and decrease the load of Lafora inclusion bodies. Now, the timing of delivery, the exact doses, the frequency of delivery, and the interval of delivery of Laforin are being fine-tuned in mice with Lafora Disease. All this information will be important when Laforin is actually delivered to patients with Lafora disease.

Monitoring Results of Laforin Gene Therapy
One other advantage gained from defining glycogen and amylopectin as substrates of Laforin is the deduction that the Lafora inclusion bodies must be made of poorly branched glycogen. This could allow the imaging of Lafora inclusion bodies in patients suffering from the disease using a positron emission labeled chemical that is part of Lafora inclusion bodies. This would be an important project for chemists -- to produce a ligand that targets a part of lafora inclusion bodies and that could be imaged on PET scans. This can be another way for monitoring the results of treatment. If Laforin can really purge excessive glycogen like the Lafora inclusion bodies, then we should be able to show the inclusion bodies decrease and even disappear on PET scans that image Lafora bodies.

Where is the Story of Lafora Disease Leading us
This story is taking us to the treatment protocols and studies that need to be developed and developed rapidly if we are to save lives.  Besides laboratory work and collaborations with various experts, this involves applications to the Institutional Review Boards to obtain approval for treatment in patients.

Thus, funds are urgently needed to develop a treatment team for Lafora Disease. This treatment team should address the following:

(1) A treatment team dedicated to

• A safety trial of laforin gene therapy in non-human simians
• Laforin human gene therapy and
• Gentamycin treatment

(2) An assay team that monitors gene replacement treatment results

(3) A PET scan team that assays turnover and purging of Lafora bodies during gene replacement treatment

December 28, 2007 - Progressive Myoclonus Epilepsy, Lafora Type

Lafora disease (LD) is characterized by fragmentary, symmetric, or generalized myoclonus and/or generalized tonic-clonic seizures, visual hallucinations (occipital seizures), and progressive neurologic degeneration including cognitive and/or behavioral deterioration, dysarthria, and ataxia beginning in previously healthy adolescents between 12 and 17 years. read more