12-05-2012, 12:17 AM
Fragile X syndrome is inherited disorder associated mostly with males. Most prominent features of the disease are mental retardation, autistic and stereotypic (repetitive) behavior. It results from FMR1 (fragile X mental retardation 1) gene impairment. FMR1 gene is located on the X chromosome and it is essential for normal mental development. Since males have only one copy of the X chromosome, impaired version of the gene will inevitably result in disease. Number of CGG triplet repeats in the FMR1 gene indicates whether gene is healthy or mutated (fully mutated gene contains > 200 repeats) and serves as a marker in genetic testing for people who are at risk of getting offspring with disease. Fragile X is also known as single-gene cause of autism. Except drugs that are used to prevent hyperactivity, anxiety, aggressiveness (known symptoms of the disease), there is no single marketed drug that is specifically designed to treat social aspect of the fragile X syndrome.
Autism is neurodevelopmental disorder. It is characterized by impaired social and communication skills, and repetitive and restrictive behavior. Genetic background of disease is not fully revealed. Investigators are not certain if disease develops after rare genetic variants are combined (several genes are implicated) or as a consequence of rare genetic mutation. Sometimes, agents that induce birth defects (heavy metals, vaccines, toxins…) could trigger autism development. Estimated costs for an individual diagnosed with autism are ~3.99 million dollars for a lifetime. Disorder is “expensive” because autistic persons demand special medical care, special education and they rarely become capable to work and earn independent from their guardians. There is no known cure for autism. Children are usually treated with antipsychotics, anticonvulsants and antidepressants to alleviate some of the disease symptoms.
Recently published article announced that fragile X syndrome initially developed drug could be beneficial for the people diagnosed with autism. Researchers didn't have necessary data about dysfunctional brain pathways associated with altered behavior (typical for neurodevelopmental disorders), but recent experiment on genetically altered animals provided more information on potential biochemistry behind disease. Experiments on the mouse with fragile X showed lower level of gamma aminobutiryc acid (neurotransmitter) in various brain areas, including hippocampus (associated with memory, activity and orientation). Scientists hypothesized that lack of this neurotransmitter could trigger social anxiety and avoidance - typical fragile X associated behavior. Arbaclofen (or STX 209) acts like gamma aminobutyric acid type B agonist (synthetic imitator). It produces the same physiological effect as naturally (organism derived) substance and compensates the lack of gamma aminobutyric acid in the body. When tested in mice, drug showed great reduction of repetitive and anti-social behavior. Study in humans showed equally promising effects. It lasted for 2 years and comprised of mostly male fragile X sufferers aged 6 to 39. Drug was submitted in 2 doses per day during six weeks. After last dose was applied, 4 to 6 weeks long pause was made before participants were evaluated. Participants were monitored for: irritability, lethargy, repetitive behavior, hyperactivity… Social avoidance and parent-nominated problem behaviors showed improvement in all subjects. Arbaclofen could be of great help in treatment of autism due to high similarity of social and behavior problems with fragile X syndrome. Future trials will provide more information on drug safety and effectiveness in both disorders.
Since pharmacological treatment is still unavailable, another treatment option should be tested. Previous studies with horses and dolphins showed that autistic children manage to relax and socialize when they are near these animals. Latest study showed that almost any animal species (dogs, cats, rabbits, hamsters…) could produce similar healing effect. Autistic kids experience difficulties in recognizing other people’s emotions and needs and animals could learn them various important skills such as ability to share and provide comfort when needed. Trick is to introduce animal to a family later. If animal is already present when autistic children is born, animal will be considered as a part of normal environment and children wouldn’t change his own behavior to comfort the animal. Also, when animal is brought to the family, interaction between the family members will change and become more intense and warmer, which will significantly affect behavior of autistic children. You just need to decide which animal species suits you the best.
Autism is neurodevelopmental disorder. It is characterized by impaired social and communication skills, and repetitive and restrictive behavior. Genetic background of disease is not fully revealed. Investigators are not certain if disease develops after rare genetic variants are combined (several genes are implicated) or as a consequence of rare genetic mutation. Sometimes, agents that induce birth defects (heavy metals, vaccines, toxins…) could trigger autism development. Estimated costs for an individual diagnosed with autism are ~3.99 million dollars for a lifetime. Disorder is “expensive” because autistic persons demand special medical care, special education and they rarely become capable to work and earn independent from their guardians. There is no known cure for autism. Children are usually treated with antipsychotics, anticonvulsants and antidepressants to alleviate some of the disease symptoms.
Recently published article announced that fragile X syndrome initially developed drug could be beneficial for the people diagnosed with autism. Researchers didn't have necessary data about dysfunctional brain pathways associated with altered behavior (typical for neurodevelopmental disorders), but recent experiment on genetically altered animals provided more information on potential biochemistry behind disease. Experiments on the mouse with fragile X showed lower level of gamma aminobutiryc acid (neurotransmitter) in various brain areas, including hippocampus (associated with memory, activity and orientation). Scientists hypothesized that lack of this neurotransmitter could trigger social anxiety and avoidance - typical fragile X associated behavior. Arbaclofen (or STX 209) acts like gamma aminobutyric acid type B agonist (synthetic imitator). It produces the same physiological effect as naturally (organism derived) substance and compensates the lack of gamma aminobutyric acid in the body. When tested in mice, drug showed great reduction of repetitive and anti-social behavior. Study in humans showed equally promising effects. It lasted for 2 years and comprised of mostly male fragile X sufferers aged 6 to 39. Drug was submitted in 2 doses per day during six weeks. After last dose was applied, 4 to 6 weeks long pause was made before participants were evaluated. Participants were monitored for: irritability, lethargy, repetitive behavior, hyperactivity… Social avoidance and parent-nominated problem behaviors showed improvement in all subjects. Arbaclofen could be of great help in treatment of autism due to high similarity of social and behavior problems with fragile X syndrome. Future trials will provide more information on drug safety and effectiveness in both disorders.
Since pharmacological treatment is still unavailable, another treatment option should be tested. Previous studies with horses and dolphins showed that autistic children manage to relax and socialize when they are near these animals. Latest study showed that almost any animal species (dogs, cats, rabbits, hamsters…) could produce similar healing effect. Autistic kids experience difficulties in recognizing other people’s emotions and needs and animals could learn them various important skills such as ability to share and provide comfort when needed. Trick is to introduce animal to a family later. If animal is already present when autistic children is born, animal will be considered as a part of normal environment and children wouldn’t change his own behavior to comfort the animal. Also, when animal is brought to the family, interaction between the family members will change and become more intense and warmer, which will significantly affect behavior of autistic children. You just need to decide which animal species suits you the best.