About 20 parent groups have formed a coalition to fight for better services for autistic children and adults, who they say are now served poorly by programs aimed primarily at mentally ill or mentally retarded people.

"Folks with autism have been on no one's radar screen," said Nina Cote, a Chadds Ford social worker who is president of the new organization, the Pennsylvania Action Coalition for Autism Services. "We would like a recognition that services right now are not meeting their needs."

The group began meeting in the spring to fight proposals to reduce mental-health services for school-age children with behavioral problems. It will incorporate this month, Cote said. It encompasses organizations from across the state.

Autistic-spectrum disorders, which include autism, pervasive development disorder, and Asperger's syndrome, are developmental disabilities caused by neurological dysfunction. Usually diagnosed in early childhood, these disorders are characterized by problems in social interaction and communication and a need for repetitive behavior.

Estimates of the prevalence of the disorders vary widely and accurate statistics for the United States are not available, according to the U.S. Centers for Disease Control and Prevention. Studies done in Europe and Asia found the disorders in 2 to 6 of every 1,000 children.

Although autistic children can have normal to high IQs, experts say that about 70 percent are mentally retarded. Some parents dispute that figure, maintaining that the communication problems inherent in autism make it difficult to measure IQ. Children with Asperger's syndrome usually have normal IQs, with some scoring above average.

The number of children diagnosed with autism is increasing rapidly. No one knows why. Cote, whose 12-year-old son Matthew is autistic, believes it is partly that children now being called autistic might once have gotten a different label. But she believes another, unknown factor is also at work.

According to state Department of Education records, the number of autistic children rose from 252 in the 1990-91 school year to 3,540 in 2000-01. During the same time period, the number of children identified as mentally retarded dropped by 6,629.

Cote and members of her group say the state needs to develop programs aimed specifically at autism.

Marilyn Eckley, director of the office of policy for the state Department of Public Welfare, said services for people with autism are an "emerging issue." The state currently is exploring how to improve care for this group and will provide a report to the new governor, she said.

State Rep. Dennis O'Brien (R., Philadelphia), who has a 16-year-old autistic nephew and considers himself a member of the new coalition, wants a standardized process for diagnosing kids with autism, better training for the people who work with them, and a treatment system based on more up-to-date research.

"There's really virtually no services for autistic kids in Pennsylvania," O'Brien said. "It was always 'the next thing' that Pennsylvania was going to get to. We don't want it to be 'the next thing' anymore."