Autism is actually a group of disorders known as autism spectrum disorders. They cause impairment of social function along with other symptoms.
Autism is actually a group of disorders known as the autism spectrum disorders. There is a wide range of symptoms within this range. The core symptoms are impairment of social function, including communication and forming relationships. Children with autism also have an unusual attachment to routine, unusual interests or ways of playing, and unusual movement patterns.
The causes of autism are currently not known, although research is proceeding to determine what the causes may be. It is clear that genetics play a role. Susceptibility to autism appears to be passed down from parents to children, although which genes are involved is not yet known (making genetic screening of embryos impossible). Certain other genetic conditions, such as Fragile X Sydnrome, lead to the symptoms of autism.
However, other environmental factors, such as air and water pollutants, may also contribute. There has been a recent rise in diagnoses of autism, which could be due to environmental factors causing the disorder. However, it is also possible that specialists’ ability to diagnose autism in those who have it has been improving, while the disorder itself is not becoming more common; there is strong debate in the scientific community over this issue.
While a possible link between autism and childhood vaccines has been extensively studied, no link has been found. Several vaccines are commonly given around the same time that parents typically notice the signs of autism, which may lead parents to blame the vaccines for the autism symptoms, when the symptoms would have appeared at the same time regardless of the vaccines.
Some of the risk factors for autism include:
• Sex of the child
• Family history
• Ages of the parents
• Preterm birth
• Other medical conditions
Boys are at a much greater risk of autism than are girls, with the reasons for this not being entirely clear.
Because genetic factors contribute to the risk of autism, family history plays an important role. The more family members have autism, the more likely the child will also have an autism spectrum disorder. A family with one child who has autism is more likely to have another child with autism.
A possible link has been established between the ages of both parents and the child’s risk of autism. Older mothers as well as older fathers are more likely to have a child with an autism spectrum disorder. However, the research on this is not conclusive, and more research is needed before this can be conclusively stated.
Babies who are born prematurely may also be at risk, although more research is also needed in this area. Current research indicates that babies born at or before 26 weeks of gestation are at increased risk; this is very early, as a normal pregnancy is expected to go to about 40 weeks.
Certain medical conditions cause symptoms that mimic those of autism, or cause the child to have an increased risk of autism. Most of these are genetic disorders. Some examples include fragile X syndrome, Tourette syndrome, and Rett syndrome. Some of these disorders that produce autism-like symptoms, like phenylketonuria, an inherited metabolic disorder, and are treatable by strictly following a special diet. Others cannot be treated.
Mayo Clinic Staff. “Autism spectrum disorder: Definition.” Mayo Clinic website (2014). http://www.mayoclinic.org/diseases-conditions/autism-spectrum-disorder/basics/definition/con-20021148
Centers for Disease Control and Prevention. “Autism Spectrum Disorder (ASD): Facts About ASD.” CDC website (2015). http://www.cdc.gov/ncbddd/autism/facts.html
National Institutes of Health. “Autism Spectrum Disorder.” MedlinePlus (2015). http://www.nlm.nih.gov/medlineplus/autismspectrumdisorder.html