Cambridge researchers have recently reported that for every three children with autism and related disorders two others remain undiagnosed.

Autism is the most common developmental disorder characterized by impaired social interaction, problems with verbal and nonverbal communication, and unusual, repetitive or severely limited activities and interests.

Latest reports have revealed that about one percent of school-aged children have an autistic spectrum disorder, indicating that the prevalence of the disease has increased by 12 times in the past 30 years.

Better recognition of the condition by both parents and doctors, wider and more accurate diagnostic criteria are accounted responsible for the recent increase in the number of autistic cases.

According to a study published in the British Journal of Psychiatry, for every three children diagnosed with autism spectrum disorder there are some two who have the criteria but are not diagnosed with the disease.

The undiagnosed cases are reported to be mild, indicating that these affected patients cope well with their families and may not need additional treatments.

Scientists stressed the accurate prevalence of children affected with the autism spectrum disorders provides authorities with better ideas in planning health, social and education services.