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| DiseaseID |
HGD61 |
| Genetic
Disorder |
Autism
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| Gene
Name |
glyoxalase I |
| Description |
Autism - or more precisely the autism spectrum disorders (ASDs) - represent a broad group of developmental disorders characterized by impaired social interactions, problems with verbal and nonverbal communication, and repetitive behaviors or severely limited activities and interests. The ASDs include a variety of medical autism diagnoses, which vary in the severity of the individual symptoms and include autistic disorder (sometimes called classical autism), Asperger's syndrome and a general diagnostic category called Pervasive Developmental Disorders (PDD). Autism has become the most commonly diagnosed childhood developmental disorder. According to the Centers for Disease Control Prevention in 2007, autism spectrum disorders now affect 1 in every 150 children in the United States. Statistics from the U.S. Department of Education and other government agencies indicate that autism diagnoses are increasing at the rate of 10 to 17 percent per year. Autism can affect any individual and is not based on ethnic, racial or social background. The incidence of autism is the same all around the world. It is four times more common in boys than in girls.
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| Symptoms |
Autism usually develops before 3 years of age and affects each individual differently and to varying degrees. It ranges in severity from relatively mild social and communicative impairments to a severe disability requiring lifelong parental, school and societal support. The hallmark symptom of autism is impaired social interaction. Children with autism may fail to respond to their name and often avoid eye contact with other people. They have difficulty interpreting what others are thinking or feeling because they don't understand social cues provided by tone of voice or facial expressions and they don't watch other people's faces to pick up on these cues. Many children with autism engage in repetitive movements such as rocking, spinning, twirling or jumping, or in self-abusive behavior such as hand biting or head-banging. Of children being diagnosed now with an autism spectrum disorder, about half will have mental retardation defined by nonverbal IQ testing and 25 percent will also develop seizures. Though most children show signs of autism in the first year of life, about 30 percent will seem fine and then regress in both their language and social interactions at around 18 months of age. About 30 percent of children with autism have physical signs of some alteration in early development such as physical features that differ from their parents (sometimes called dysmorphic features), small head size (microcephaly) or structural brain malformations
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| Causes |
Autism has no single, identifiable cause. The disorder seems to be related to abnormalities in several regions of the brain. Researchers have identified a number of gene defects associated with autism.
Families with one autistic child have a one in 20 chance of having a second child with the disorder. In some cases, relatives of autistic children show mild impairments in social and communication skills or engage in repetitive behaviors.
Children with symptoms of autism have a higher than normal risk of also having:
Fragile X syndrome, which causes mental retardation
Tuberous sclerosis, in which tumors grow in the brain
Tourette's syndrome
Epilepsy
Some people believe autism is caused by vaccines — particularly the measles-mumps-rubella vaccine (MMR), as well as vaccines containing thimerosal, a preservative that contains a very small amount of mercury. But extensive studies have shown no link between vaccines and autism. |
| Diagnosis |
Diagnosis of autism is based on standardized testing plus a clinical evaluation by an autism specialist. These professionals are usually psychologists, psychiatrists, developmental pediatricians, pediatric neurologists or medical geneticists. The diagnosis of autism is made when there are a specific number of symptoms as defined by the Diagnostic and Standard Manual of Mental Disorders (DSM-IV). Some commonly used diagnostic tests are the CARS (Childhood Autism Rating Scale), the ABC (Autism Behavior Checklist) and the GARS (Gilliam Autism Rating Scale). Formal diagnosis by an autism specialist usually depends on completing the ADOS (Autism Diagnostic Observation Scale), and ADI-R (Autism Diagnostic Interview-Revised). The CHAT (Checklist for Autism in Toddlers) is often used in pediatrican's offices to screen for autism symptoms. When physical features, small head size or brain malformations are present or there is a family history of relatives with autism, genetic testing such as chromosome analysis and single-gene testing is done.
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| Treatment |
There is currently no cure for autism. However, autism can be managed and shaped at a young age, even as early as pre-school. Early intensive therapy can have a positive effect on development later in life. Treatment of autism involves medical and behavioral therapies to help children with conversational language and social interactions. Treatment also involves helping children decrease their repetitive, self-stimulatory behaviors, tantrums and self-injurious behavior. Medications can help treat specific symptoms such as aggressive or self-injurious behavior, inattention, poor sleep and repetitive behaviors. However, no medications are autism specific and medications should be used in conjunction with a family-centered, behavioral and educational program. |
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