Autism Information
Autism is a brain development disorder that is characterized by impaired social interaction and communication, and restricted and repetitive behavior, all starting before a child is three years old. This set of signs distinguishes Autism from milder Autism spectrum disorders (ASD) such as Asperger's Syndrome. Autism has a strong genetic basis, although the genetics of Autism are complex and it is unclear whether ASD is explained more by multi gene interactions or by rare mutations.
In rare cases Autism is strongly associated with agents that cause birth defects. Most recent reviews estimate a prevalence of one to two cases per 1,000 people for Autism, and about six per 1,000 for ASD, with ASD averaging a 4.3:1 male-to-female ratio. The number of people known to have Autism has increased dramatically since the 1980s, at least partly as a result of changes in diagnostic practice; the question of whether actual prevalence has increased is unresolved.
Autism Causes
Autism has a strong genetic basis, although the genetics of Autism are complex and it is unclear whether ASD is explained more by multi gene interactions or by rare mutations with major effects. Early studies of twins estimated heritability explains more than 90% of the risk of Autism, assuming a shared environment and no other genetic or medical syndromes. However, most of the mutations that increase Autism risk have not been identified. Typically, Autism cannot be traced to a Mendelian (single-gene) mutation or to a single chromosome abnormality, and none of the genetic syndromes associated with ASDs has been shown to selectively cause ASD.
There may be significant interactions among mutations in several genes, or between the environment and mutated genes. Numerous candidate genes have been located, with only small effects attributable to any particular gene. The large number of Autistic individuals with unaffected family members may result from copy number variations (CNVs)-spontaneous deletions or duplications in genetic material during meiosis. Hence, a substantial fraction of Autism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the Autism is not present in the parental genome.
Autism Treatments
The main goals of treatment are to lessen associated deficits and family distress, and to increase quality of life and functional independence. No single treatment is best and treatment is typically tailored to the child's needs. Intensive, sustained special education programs and Behavior Therapy early in life can help children acquire self-care, social, and job skills, and often improve functioning and decrease symptom severity and maladaptive behaviors.
Autism is a brain development disorder that is characterized by impaired social interaction and communication, and restricted and repetitive behavior, all starting before a child is three years old. This set of signs distinguishes Autism from milder Autism spectrum disorders (ASD) such as Asperger's Syndrome. Autism has a strong genetic basis, although the genetics of Autism are complex and it is unclear whether ASD is explained more by multi gene interactions or by rare mutations.
In rare cases Autism is strongly associated with agents that cause birth defects. Most recent reviews estimate a prevalence of one to two cases per 1,000 people for Autism, and about six per 1,000 for ASD, with ASD averaging a 4.3:1 male-to-female ratio. The number of people known to have Autism has increased dramatically since the 1980s, at least partly as a result of changes in diagnostic practice; the question of whether actual prevalence has increased is unresolved.
Autism Causes
Autism has a strong genetic basis, although the genetics of Autism are complex and it is unclear whether ASD is explained more by multi gene interactions or by rare mutations with major effects. Early studies of twins estimated heritability explains more than 90% of the risk of Autism, assuming a shared environment and no other genetic or medical syndromes. However, most of the mutations that increase Autism risk have not been identified. Typically, Autism cannot be traced to a Mendelian (single-gene) mutation or to a single chromosome abnormality, and none of the genetic syndromes associated with ASDs has been shown to selectively cause ASD.
There may be significant interactions among mutations in several genes, or between the environment and mutated genes. Numerous candidate genes have been located, with only small effects attributable to any particular gene. The large number of Autistic individuals with unaffected family members may result from copy number variations (CNVs)-spontaneous deletions or duplications in genetic material during meiosis. Hence, a substantial fraction of Autism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the Autism is not present in the parental genome.
Autism Treatments
The main goals of treatment are to lessen associated deficits and family distress, and to increase quality of life and functional independence. No single treatment is best and treatment is typically tailored to the child's needs. Intensive, sustained special education programs and Behavior Therapy early in life can help children acquire self-care, social, and job skills, and often improve functioning and decrease symptom severity and maladaptive behaviors.
