Autism is as misunderstood as it is frightening for parents of young children. The fact that the Centers for Disease Control Prevention estimate 1 child in 100 births is autistic makes it far more relevant than some closet mental illness. Most certainly, it's hard to dismiss the fact that 1.5 million Americans are believed to have with some form of autism. And researchers say that number is rising.

Statistics cited by the U.S. Department of Education indicate the number of children affected by autism is growing 10 to 17 percent per year. At this rate, it's estimated that the prevalence of autism could reach 4 million Americans in 10 years.

What is it?

Autism is a spectrum disorder, a group of disorders with similar features. It is the most common of the pervasive developmental disorders. One person may have mild symptoms, while another may have serious symptoms, but they both have an autism spectrum disorder. A milder form of autism called Asperger syndrome has autism-like symptoms. But those diagnosed with Asperger have normal intelligence and verbal skills.

According to the Autism Society of America, autism typically appears during the first two years of a child's life. The disease is the result of a neurological disorder, which affects the brain's function and restricts skills development in the areas of social interaction and communication.

Researchers say there is no known single cause for autism, but most agree it's caused by abnormalities in brain structure or function. Brain scans of children with autism show differences in the shape and structure of the brain versus neuro-typical children. Some theories establish a link between heredity, genetics and medical problems. Three groups seem to have a higher risk for autism spectrum disorders: boys, siblings of those with autism and people with certain other developmental disorders.

Common traits

While every person with autism has a unique personality and combination of characteristics, some may experience only slight language delays and greater challenges with social interactions. But there are some common traits to note:

  • Has an insistence on sameness; resistance to change
  • Has difficulty expressing needs; uses gestures or pointing instead of words
  • Repeats words or phrases in place of normal, responsive language
  • Laughs (or cries) for no apparent reason; shows distress for reasons not apparent to others
  • Prefers being alone; aloof manner
  • Displays tantrums