Explainer: What is autism? | Science News for Students

Explainer: What is autism?

Some people have a mild form, others a type that makes it hard to talk or interact with others
Apr 3, 2014 — 9:01 am EST

One in every 68 children born in the United States develop some form of autism. The disorder can, in some instances, lead to extreme social isolation or intense overreactions to sounds and other sensory stimuli.  


Autism refers to a group of closely related disorders that affect how the brain develops. Experts use one blanket term —“autism spectrum disorders” —to refer to the whole group.

Autism isn’t a disease that can be passed from one person to another. Nor do the vaccines commonly given in childhood cause autism, scientists say. The disorder appears to be due, at least in part, to the genes we inherit from our parents. However, scientists say genes alone can’t explain why some kids get autism and others don’t. Many other still-unknown causes likely contribute.

Autism emerges when certain parts of a child’s brain don’t develop normally. The disorder often causes affected people to have trouble interacting with others. They can struggle to communicate. They also tend to repeat some particular behavior or action over and over.

The disability is becoming more common, though no one knows exactly why. About one out of every 68 children in the United States has been diagnosed with an autism spectrum disorder. Boys seem to be at much greater risk. In fact, doctors diagnose 1 out of every 42 boys with autism but only 1 out of every 189 girls.

Harmful changes in certain genes have been linked to autism. And boys appear to need far fewerof them to develop the disorder. That was the conclusion of a study published March 6, 2014, in the American Journal of Human Genetics

Researchers use the word “spectrum” because the symptoms of autism can vary greatly from one individual to another. Some children may develop a mild version that’s barely noticeable. It’s called Asperger’s syndrome, or sometimes high-functioning autism. People with it may have no trouble speaking, thinking or remembering things. In fact, they often have excellent language skills. They can, however, find it hard to interact with other people. Some are clumsy, repeat the same actions or use odd words when they talk.

Others can have more severe form of autism. In some cases, they will not be able to talk or take care of themselves.

Some scientists like to say that the brain is “wired differently” in people with autism. That means they often see, hear and feel the world in ways that others do not.

Power Words

Asperger’s syndrome    A specific kind of autism spectrum disorder that is often called high-functioning autism. Although this form of autism does not impact a person’s intelligence or speech, the person may still struggle to interact and communicate with other people.

autism spectrum disorders    A set of developmental disorders that interfere with how certain parts of the brain develop. Affected regions of the brain control how people behave, interact and communicate with others and the world around them. Autism disorders can range from being very mild to being very severe. And even a fairly mild form can limit an individual’s ability to interact socially or communicate effectively.

diagnose   To analyze clues or symptoms in the search for their cause. The conclusion usually results in a diagnosis — identification of the causal problem or disease.

gene   A segment of DNA that contains the instructions for making a protein. Those proteins govern the behavior of a cell — or large groups of cells. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

vaccine   A biological mixture that resembles a disease-causing agent, given to help create immunity to a particular disease.


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Further Reading

Learn more about autism spectrum disorders from the National Institute of Mental Health.