Hyperlexia is characterized by an above average ability to read accompanied with a below average ability to understand spoken language. The symptoms are closely related to those of autism and some consider it to be an autism spectrum disorder, whereas others contest it to be a completely different condition.
Often, hyperlexic children will have a precocious ability to read but will learn to speak only by rote and heavy repetition, and may also have difficulty learning the rules of language from examples or from trial and error, which may result in social problems.
Children with hyperlexia may recite the alphabet as early as 18 months, and have the ability to read words by age two and sentences by age three. Many are overly fascinated with books, letters, and numbers. Parents delay finding help because they believe that their child may be a struggling genius. Hyperlexia often coexists with high functioning autism or Asperger syndrome.
Despite hyperlexic children's precocious reading ability, they may struggle to communicate verbally. Their language may develop in an autistic fashion using echolalia, often repeating words and sentences. Often, the child has a large vocabulary and can identify many objects and pictures, but struggles to express this verbally. Spontaneous language is lacking and their pragmatic speech is delayed. Hyperlexic children often struggle with Who? What? Where? Why? and How? questions. Between the ages of 4 and 5 many children make great strides in communicating and much previous stereotypical autistic behavior subsides.
Often, hyperlexic children have a good sense of humor and may laugh if a portion of a word is covered to reveal a new word. Many prefer toys with letter or number buttons. They often obsess over numbers in real life, such as Gas Station prices, Highway Exit Numbers, Copyright Dates, etc. Many have no issues in reading large numbers such as trillions, googals and reciting digits of pi.
They may have olfactory, tactile, and auditory sensory issues. Their diets may be picky, and often toilet training can be difficult. They may struggle to understand social skills. Social stories can be helpful in developing effective age-relative social skills, and setting a good example is crucial.
Hyperlexia also continues into adulthood. Many hyperlexics are fascinated by foreign languages and scripts and can teach themselves to read almost any language. Languages like Chinese, Japanese and Korean are common examples, due to the complexity of the scripts and the feeling of achievement felt by reading them.
Despite voluminous research and professional journal articles pertaining to the relationship between hyperlexia and autism, very little research exists on treatment methodologies. In 2004, an article in the Journal of Autism and Developmental Disorders described three possible interventions to support reading comprehension. Only anaphoric cuing proved to produce measurable results. 
San Diego teacher and action researcher Sara Finegan writes about her work using anaphoric cuing on students with autism on her website, Readers with Autism, which also contains other articles about interventions to support reading comprehension in students on the autism spectrum. Finegan used the O'Connor and Kline article to develop her own technique for anaphoric cuing which was first described in Masters Project at California State University in San Marcos.
- ↑ O’Connor, I.M. & Klein, P.D. (2004). Exploration of strategies for facilitating the reading comprehension of high-functioning students with autism spectrum disorders. Journal of Autism and Developmental Disorders, 34(2): 115 -127