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L'X fragile sera vaincu | Fragile X will be conquered

Archive for fragile x

AUTISME et X FRAGILE: Même mécanisme génétique, même espoir de traitement?

Neuron et Science Transational Medicine |

(…) Leurs travaux indiquent donc une convergence possible des mécanismes causant l’autisme et l’X fragile: L’association présentée dans l’étude n’est pas avec le gène FMR1 lui-même, mais avec les gènes qui sont «en aval» de celui-ci. Ce sont les gènes qui produisent des régulateurs du gène FMR1 et, en gros l’empêchent de produire correctement la protéine FMRP. « Nous avons aujourd’hui une forte preuve statistique sur le lien entre l’autisme et le syndrome de l’X fragile », explique le Dr Wigler. «Notre découverte a des implications importantes pour la thérapie des TSA et montre que l’autisme est en grande partie un désordre moléculaire de la neuroplasticité, le mécanisme par lesquel notre système nerveux s’adapte aux changements.”

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FRAXA Research Outlook 2012 – Treatment Trials and the Next Wave of New Drugs

Fragile X research continues to progress at a break-neck pace and 2012 promises to be a watershed year: the landscape may be very different by this time next year!

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Drug trials for fragile X syndrome lead the way for autism therapies

Randi Hagerman, Sfari.org |

A number of targeted trials on drugs that have the potential to reverse many of the behavioral and cognitive features of fragile X syndrome, are under way. Human and animal studies have shown that these medications can reverse many of the neurobiological and phenotypic features of fragile X syndrome. Along with these new trials, we will need accurate endpoints that can reliably measure the drugs’ effectiveness.

Fragile X syndrome is the most common inherited cause of intellectual disability and single-gene cause of autism. The full mutation has more than 200 repeats of a DNA sequence — CGG — at the front end of the FMR1 gene. This repeat number leads to a shutdown of the gene and a lack of the protein that it normally produces, fragile X mental retardation protein, or FMRP. The lack of FMRP causes fragile X syndrome and intellectual disability, in addition to autism, in 30 percent of individuals and pervasive developmental disorder-not otherwise specified in another 30 percent.

Between 55 and 200 repeats in the FMR1 gene causes what is called a premutation. The premutation leads to autism at a much lower rate — approximately ten percent of boys and less than two percent of girls.

The fragile X mutations cause autism through different molecular pathways. The absence or deficiency of FMRP affects the levels of many genes important for synaptic plasticity — how neurons strengthen important connections — and the outgrowth of neurites, the formation of new connections between neurons.

The fragile X premutation leads to higher levels of the RNA message for the FMR1 gene, which can bind to important proteins and dysregulate neuronal functions, leading to early cell death.

Promising trials:

Novartis and Roche both have an inhibitor of mGluR5, which activates a pathway that is overactive in those with fragile X syndrome.

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New research aims to shed light on abnormal brain development

Via Eurekalert |

Vancouver, BC – Local researchers are finally on the road to developing targeted treatments for serious, life-long disabilities such as autism and schizophrenia, thanks to new genomics research focusing on abnormal brain development.

With funding from Genome British Columbia, Dr. Daniel Goldowitz of the UBC Department of Medical Genetics and the Centre of Molecular Medicine and Therapeutics, is opening the mysterious world of the developing brain by mapping the genes in the cerebellum and studying which genes influence abnormal development.

The $330,000 (CDN) project, Functional Characterization of the Transcriptional Network Driving Mammalian Brain Development, will determine which genes are activated and essential during brain development so researchers can better understand development-related diseases such as autism spectrum disorder, schizophrenia and fragile X mental retardation. One key to understanding these disorders lies in the study of a region of the brain that has been difficult to map, the cerebellum.

If the researchers can identify key genes involved in the early development of the cerebellum and that influence the rest of brain development, they may be able to encourage or restart plasticity, the brain’s ability to heal and change. These discoveries are anticipated to lead to new drugs and cognitive treatment for people with abnormal brain development.

“All of our incoming sensory information is received by the cerebellum where it can be compared and contrasted,” says Goldowitz. “So you can imagine if there is a mismatch between information coming in and going out – that there would be a serious problem. You might create another world to try and help you cope like with schizophrenia, or within autism you might shut down incoming information to cope.”

“Our long term goal would be to develop tools for early diagnosis of, and possible therapies for brain disorders such as autism,” says Goldowitz. Increased knowledge and understanding of the genetic wiring of the cerebellum will also open the door to new therapeutics for deadly childhood brain cancers.

Working in close collaboration with Dr. Harukazu Suzuki and colleagues at the world-renowned RIKEN Institute in Japan, the researchers will use cutting-edge genomic technology to identify gene regulatory networks, which control how the cerebellum develops.

The partnership with the RIKEN Institute will allow the researchers to capitalize on world-leading genomic technologies to study the gene expressions and interactions of the cerebellum at a level of resolution never before attained.

“Up until now, we couldn’t manage the data sets because they were just too large,” says Goldowitz. “Through with this international partnership, we should be able to see which genes are turning on other genes so that we can build networks that show the architecture of the developing cerebellum.”

“Genome BC is pleased to support this innovative and exciting research in brain development,” says Dr. Alan Winter, President and CEO of Genome BC. “This is exciting on many levels. It offers promising new therapies for developmental and neurological disorders and makes practical use of the latest genomic technologies. In addition, it extends BC scientific excellence into new international collaborations with esteemed researchers at the RIKEN Institute in Japan.”

Genome BC has funded this project as part of its Strategic Opportunities Fund, which funds projects with direct impact on industry and other end-users.

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Seaside Therapeutics Advances Fragile X Drug

By Lisa Jarvis, cenblog.org |

Some great news out today for parents of kids with Fragile X, a neurological disorder that is also the most common genetic cause of autism: Seaside Therapeutics has begun a Phase III trial of STX209, which could potentially be the first drug available to treat the underlying symptoms of the disorder.

Fragile X, a disorder that, like autism, impacts the way brain cells communicate, is caused by a mutation to the FMR1 gene. People with Fragile X suffer from over-stimulated synapses, creating a kind of signaling noise that prevents them from easily learning through experience.

STX209 is a single-isomer version of the already-approved muscle-relaxant baclofen, a GABA-B receptor agonist. It was identified as a potential treatment for Fragile X after doctors noticed a child who was given the drug to treat a gastrointestinal problem also showed improvements in cognitive function and behavior. Seaside separated out the two isomers and found the efficacy in one isomer and the majority of the negative side effects in the other.

Those following drug development in Fragile X know that both Novartis and Roche have seen promising results in small Phase II trials of compounds that act like a brake on mGluR5, a neurotransmitter receptor that MIT neurologist Mark Bear found to be overstimulated in people with Fragile X. STX209 works by dampening the activity of mGlur5, although the Seaside has another compound in development that works directly on the protein.

Seaside expects to sign up 120 people, ages 12 to 25, with Fragile X, in its Phase III trial, and start a second study for kids ages 5 to 11 in early summer. The trial ages are notable because the Novartis and Roche trials were both conducted on adults ages 18 and up; because the side effect profile of baclofen is well understood, FDA has been willing to allow STX209 to be tested in children.

The continued success of the drug could have implications for the broader autism community. Seaside has already begun testing STX209 in autism with the idea that some of the neurological breakdown could happen along that mGluR5 signalling pathway. And although the trial was small—and was open label, meaning doctor’s knew the kids were getting the drug—the biotech firm was encouraged to see signs of similar improvements in social behavior and cognition as in the Phase II study in Fragile X.

Ultimately, Seaside hopes to develop drugs for other single-gene mutations with links to autism, with the hopes of helping both those patients as well as the broader autism population. The story is still evolving, but it’s encouraging nonetheless to see some good news in a area that is seriously in need of new treatments.

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Seaside Therapeutics commences STX209 Phase 3 study in fragile X syndrome

Via news-medical.net /Published on June 2, 2011 at 8:19 AM |

Seaside Therapeutics, Inc. announced today the initiation of a randomized, double-blind, placebo-controlled Phase 3 study to evaluate the effects of STX209 (arbaclofen) on social impairment in adolescents and adults (ages 12 to 25) with fragile X syndrome. A second study in children (ages 5 to 11) is expected to begin in early summer. STX209 is an oral selective gamma-amino butyric acid type B (GABA-B) receptor agonist.

“STX209 may be able to play a much needed role in improving the core symptoms of fragile X syndrome and in helping patients and their families achieve an improved quality of life,” said Randall L. Carpenter, M.D., President and Chief Executive Officer of Seaside Therapeutics. “In our Phase 2 study, we were very excited to observe clinically meaningful improvements in social impairment in patients receiving STX209—marking the first time a drug candidate has positively impacted a core symptom of fragile X syndrome. The Phase 3 study is the most comprehensive study ever undertaken in patients with fragile X syndrome and represents the first time that a drug candidate will be evaluated for a core symptom of fragile X syndrome as the primary endpoint.”

Source: Seaside Therapeutics

Wisdom teeth and stem cells

ATLANTA — “Families that have children with special needs are desperately seeking answers.” And one of the last places Gail Heyman ever thought to look was in her son’s mouth. But there in the back, in the aptly named wisdom teeth, answers for researchers at Emory.

“Scott was not diagnosed until he was 9 years old.”

Scott Heyman has Fragile X, a genetic disorder. Scott’s mother Gail says, “Fragile X is the leading cause of mental impairment that is inherited.”

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Closing in on targeted treatments for fragile X

UC Davis Health System, march 16 |

Maude Brownlie, who lives in Melrose, Scotland, wasn’t aware of her head tremors until her young granddaughter pointed it out. Over the next few years, the tremors worsened and spread, causing balance problems that resulted in several falls and phantom pains. She also began losing her words. A dynamic woman who adored being a grandmother, she became irritated, fatigued and depressed by her physical and cognitive decline.

Disheartened by the lack of information from her own physicians, Brownlie sought answers. Her daughter, whose sons had been diagnosed with fragile X syndrome, suggested she meet with the team at the MIND Institute at UC Davis Health System.

Randi Hagerman, medical director of the MIND Institute, discovered that Brownlie was a carrier of the premutation of fragile X. She diagnosed Brownlie with fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative condition that was causing her symptoms.

“I was very much against going and felt that it would be a complete waste of their time and our money,” she says. “How wrong I was!”

Fragile X is a family of genetic conditions that includes FXTAS, which Hagerman and her fellow researcher and husband, Paul, a molecular biology physician-scientist and director of the Neuro- Therapeutics Research Institute, discovered in 2001. It also includes fragile X syndrome (FXS), the most common cause of inherited intellectual disability and the most common known single-gene cause of autism, and fragile X-associated primary ovarian insufficiency (FXPOI), a problem with ovarian function that can lead to infertility and early menopause.

Brownlie and her family had consulted with the right team. Researchers at the MIND Institute are at the epicenter of robust basic and translational science research into psychopharmacological treatments for FXS and FXTAS.

“This is a most exciting time for us,” says Randi Hagerman, also the co-founder of the world-renowned National Fragile X Foundation. “Our goal is to reverse the neurobiological, structural and hopefully cognitive and behavioral abnormalities of fragile X.”

One in 129 women is estimated to carry the fragile X premutation. Like Brownlie, women typically show no neurodevelopmental deficits in youth. One in 3,600 individuals has the full mutation, which results in fragile X syndrome. Approximately one-third of all children diagnosed with FXS have autism and another third have some features of autism spectrum disorder (ASD).

The treatments in trial for FXS are designed to address the core of the genetic problem: the absence or deficiency of a single protein, the fragile X mental retardation protein (FMRP).

FMRP is a “mother protein” that controls the translation of about 800 genetic messages, many of which are important for synaptic plasticity. With fragile X syndrome, this protein is eliminated or deficient, thus interfering with normal brain development and learning.

One affected system, for example, is the metabotropic glutamate receptor 5 system (mGluR5), an excitatory system that leads to the weakening of synaptic connections. In a regularly functioning system, FMRP works something like a gatekeeper to keep mGluR5 activity in check. In the absence of FMRP, the gate is left open, and enhanced activity leads to weak synaptic connections throughout the brain. This leads to anxiety, hyperactivity, impulsivity, a short attention span and social deficits that can include autism.

In a pilot study reported in the Journal of Medical Genetics, researchers at the MIND Institute and Rush University Medical Center, Chicago, found that an mGluR5 antagonist called fenobam helped to lower mGluR5 activity, which calmed behavior and reduced hyperactivity and anxiety in patients with FXS. The New York Times reported in April 2010 that another antagonist was successfully used in a European medical trial. The principal investigators of that study were trainees from the MIND Institute: Sebastien Jacquemont and Vincent Des Portes.

The remarkable promise of mGluR5 antagonists is spurring further research. The MIND Institute has three additional clinical trials scheduled throughout 2010 and 2011.

Two pharmaceutical treatments that show particular promise for younger patients are arbaclofen and minocycline. A controlled trial of arbaclofen in children and adults with FXS was completed in April 2010, and preliminary positive results were presented at the 2010 International Meeting for Autism Research. A six-month double-blind controlled trial of minocycline, funded by the National Fragile X Foundation, began in February 2010 and studies children ranging in age from 3.5 years to 16 years.

Also under way is a study of memantine, a medication used to treat moderate to severe Alzheimer’s disease. The study is funded by the National Institutes of Health for people with the fragile X premutation who have FXTAS – like Brownlie. FXTAS is of special interest because it reveals a generational gap that the Hagermans uncovered.

“Current research on FXS and autism has led to dramatic advances in understanding aging and even dementia,” Randi Hagerman explains. “We now know the premutation can cause problems in adult life, including depression, anxiety, mood instability, early cognitive decline, difficulties with ovarian failure and FXTAS. It’s all related.” Brownlie found relief with a treatment regimen of memantine and an antidepressant. When she returned to the MIND Institute for an annual evaluation, her tremors had been greatly reduced and her depression was gone.

“She was a completely changed woman,” Hagerman says.

“My experience with the MIND Institute and UC Davis has had a hugely beneficial outcome,” Brownlie says. “I am really enjoying … my ‘new self.’ My energy levels, self-esteem and confidence are back to what they were five years ago. My aim now is to persuade the other FX carriers in my family to be assessed by the team at the MIND Institute. Or, just maybe, some interested professionals in the U.K. will come on board and extend the research so that treatment is available here.”

“Our team is on the cusp of finding effective drugs to mitigate fragile X syndrome’s devastating impact,” Hagerman says, “and we are leading the way to restoring quality of life for all generations of families affected by fragile X.”

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Left behind

Deborah Rudacille, Sfari.org |

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Meanwhile, a survey exploring the lives of 328 men and women with fragile X syndrome found that those who have both fragile X and autism have less independence than those with fragile X alone. The most common leisure activities among both men and women with fragile X syndrome are watching television, playing video games and listening to music — all solitary in nature, the researchers note.

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Reported Rise in Autism Coincides with Rise in Autism Treatment Drugs

By BC Bass |

SAN NARCISO, Calif. — According to figures released by the Centers for Disease Control and Prevention (CDC), autism disorders have increased more than 60 percent over the last four years. Behavioral health scientist Catherine Rice, Ph.D., says it’s difficult to tell how much this data reflects actual increases in the disorder versus improvements in identifying conditions. Geraldine Dawson, Ph.D., the chief science officer for Autism Speaks, told WebMD, “Two decades ago, we were looking at a prevalence of one in 5,000 children. Now we’re looking at one in 100. That really is a staggering increase.”

But this dark cloud has a silver lining. Scientists think they may have identified the mutated chromosome responsible for causing the onset of the disorder. More importantly, and perhaps more presciently, pharmaceutical companies released an unprecedented number of drugs targeted at suppressing it, months before it was even discovered.

Fragile X
Mark Bear, who directs the Picower Institute for Learning and Memory at MIT, has discovered a system in the brain that could dramatically improve the quality of life for thousands of people with Fragile X.

Fragile X is a mutation on the X chromosome that can cause mental retardation and autism. Unlike the hotly debated Chemical X, which bestows superhuman abilities and the power of flight on prepubescent girls in undocumented studies, Fragile X appears to disrupt a system in the brain that regulates synapses — the connections between brain cells. Bear equated the condition to a car with missing breaks. Others have equated it to a marathon bong session at a Burning Man festival.

“Dire as it may seem, this news couldn’t have come at a better time,” said Quint Scroop, a senior lobbyist and moral champion from Pharmaceutical Research and Manufacturers of America (PhRMA), which has also lined up with a far-right Christian advocacy group to fight legislation supporting abortion-rights issues.

“Coincidentally enough,” Scroop continued, “the tremendous increase in the number of autism cases being diagnosed by doctors correlates directly to announcements by pharmaceutical companies that they have identified a vast array of drugs that can be used to treat autism. With so many of these doctors under contract with drug manufacturers, access to the medications is expedited. It’s really a win-win for autistics.”

New Drugs Winning the War
“I’ve always found the term ‘war on drugs’ quaint,” Scroop opined. “It means there’s a war and that drugs are winning. Well, there is a war — against this crippling disorder we call autism. There’s no reason why the people who suffer from it need to remain pariahs, throwing in their lots with other incurables. And, yes, the drugs will prevail.”

Scientists employed by leading pharmaceutical companies have indeed identified several drugs that seem to correct the problems inherent to Fragile X Syndrome. And they’re busy making even more. Cambridge, MA-based Seaside Therapeutics, for example, revealed that is has raised $30 million to pursue clinical trial development of new therapies for Fragile X and autism.

“Some of the most exciting developments with these drugs are the side benefits,” extolled a spokesperson for another leading drug producer. “In addition to curbing complications with Fragile X, our drugs are also proving to make children more docile and controllable. They stop toddler depression, abate restless leg syndrome, and even increase penis size.”

With the exception of commonplace side effects such as nausea, diarrhea, nose bleeds, suicidal thoughts, risk of stroke, irrational fear of water, and accelerated weight gain, the drugs are sure to succeed.

“We’re really pushing hard for legislation to enforce mandatory autism screening and treatments in the public schools,” boasted Scroop. “Parents should listen to and proactively follow the screening recommendations of our physicians, regardless of whether they have concerns.”

The proposed — and certain to pass — public testing and treatment program will be administered initially by only those doctors approved by the drugs’ manufacturers.

“It’s a safety thing,” Scroop explained.

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New drug rescues function in fragile X syndrome

Deborah Rudacille, Sfari.org |

A new drug appears to relieve symptoms of fragile X syndrome by blocking the over-production of a key protein in a subset of people with the disorder, according to a 6 January study in Science Translational Medicine1.

Fragile X syndrome, an inherited form of mental retardation with features of autism, is caused by a mutation in the FMR1 gene. Some individuals with fragile X have the full mutation, which shuts down production of the protein, FMRP, needed to form healthy connections between neurons. Others have a partial mutation, which spares some FMRP production.

FMRP acts as a brake on components of the mGluR5 pathway, which run riot in individuals with the full mutation, leading to severe symptoms of the disorder. The new study shows that the drug AFQ056, made by Swiss pharmaceutical giant Novartis, blocks production of mGluR5, lessening the severity of symptoms in individuals with the full mutation. Individuals with partial mutations show more variable results.

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How do the Behaviors Seen in Persons with Fragile X Relate to Those Seen in Autism?

The National Fragile X Foundation |

Many parents are confused about their child’s diagnosis. On the one hand, they’ve been told that their child has autism, “autistic spectrum disorder,” or some degree of autistic-like characteristics. In addition, they may have also been told that their child has fragile X syndrome or that he or she is going to be tested for fragile X.

The association between autism and fragile X was first reported by Brown et al. (1982) and was subsequently confirmed by many others leading to an extensive field of research. In discussing this association it is important to remember that autism is defined behaviorally using the criteria of the DSM IV manual which include lack of social reciprocity or responsiveness, abnormal use of language and communication, and a restricted repertoire of activities and interests. Autism is a heterogenous disorder which means that there are several known causes of autism including phenylketonuria (PKU), tuberous sclerosis and 15q duplications. However fragile X is the most common known cause of autism so far identified. Autism is strongly genetic and it is likely that the inheritance of multiple genes predisposing an individual to autism is necessary in many cases for the full behavioral syndrome to be manifested.

The typical features of fragile X syndrome (FXS) i.e. hand biting, hand flapping, poor eye contact, shyness, and social anxiety are probably related to the sensory hyperarousal that has been documented by many investigators including Belser and Sudhalter (1995), Miller et al. (1999), and Roberts et al.(2002). These features are often also referred to as autistic-like features because they can be seen in individuals who have autism without fragile X. Most children with fragile X, however, are interested in social interactions and do not meet the diagnostic criteria for autism.

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Mouse model hints at Alzheimer’s therapies for fragile X

Sfari.org |

Lowering the levels of proteins associated with Alzheimer’s disease can improve symptoms of fragile X syndrome in mice, according to a poster presented Wednesday at the Society for Neuroscience annual meeting.

Fragile X syndrome is the most common inherited cause of cognitive disability, and the most common known cause of autism. It is caused by a mutation in the FMR1 gene, which encodes FMRP, a regulatory protein.

One of FMRP’s targets is amyloid precursor protein or APP. In turn, APP can be processed by the body to form beta-amyloid, the molecule that forms plaques in the brains of people with Alzheimer’s disease.

“Our previous work has shown that amyloid precursor protein and beta-amyloid are increased in FMR1 knockout mice,” says study leader Cara Westmark, associate scientist in pathology and laboratory medicine at the University of Wisconsin.

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Mark Bear’s Fight To Decode Autism

Après avoir fait la Une du New York Times, le 30 avril 2010, l’X fragile et Mark Bear défraient la manchette du magazine Forbes.

After ‘front paging‘ the New York Times, Fragile X makes headlines again, this time on Forbes.

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Robert Langreth, 11.18.10, 01:40 PM EST, Forbes Magazine dated December 06, 2010 |

MIT researcher Mark Bear thinks that some forms of autism and mental retardation may be treatable with drugs already on laboratory shelves.

Mark Bear, 53, has been fixated on understanding the brain since he was 6–when he saw news commentators speculating about John F. Kennedy’s brain functioning after the shooting. He later became a neuroscientist, now at the Massachusetts Institute of Technology, spending most of his career doing basic research on how the brain’s cells form connections during learning.

Today researchers are buzzing about Bear and his radical new theory that offers a real glimmer of hope that some forms of autism may be treatable with drugs. The causes of autism have mystified scientists for decades. It has been blamed on everything from genes to environmental toxins to the discredited concept that childhood vaccines are the culprit.

Bear’s work suggests that a specific class of drug already sitting on drug company shelves may help patients with an inherited disease called fragile X syndrome, a common cause of autism. It hits one in 5,000 kids and causes mental retardation, anxiety and autism-like symptoms. While years of research remain, Bear theorizes those types of drugs might have application beyond fragile X and into autism in general.

In the wake of his results Roche ( RHHBY.PK – news – people ) and Novartis ( NVS – news – people ) have begun testing an old class of experimental anxiety drugs called mGluR5 inhibitors in fragile X patients. Seaside Therapeutics, which Bear cofounded, licensed a similar drug from Merck ( MRK – news – people ) that is set to enter tests in fragile X patients early next year. Another Seaside drug showed promising early results in a study of 28 autism patients. (Bear owns 5% of the company.)

“I have been in this field for 25 years, and these last two years have been the most exciting in my career,” says Randi Hagerman, a developmental pediatrician at the MIND Institute at UC, Davis who is testing several of the drugs.

Bear’s work in fragile X started with a chance encounter a decade ago with Emory University geneticist Stephen Warren, who discovered the gene for fragile X in 1991. Bear gave a speech about how protein production was needed for certain basic cellular processes involved in memory. That grabbed Warren’s attention. He knew that the same gene that caused fragile X also helped control protein production. “After his talk I leaned over and said, ‘I have a mouse you have to look at,'” Warren says.

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