• There is no simple answer to this question since autistic disorder has many causes. Several inherited disorders are associated with autistic-like behavior. Some of these disorders include fragile X syndrome, tuberous sclerosis complex (TSC), and neurofibromatosis type1 (NF1). If testing indicates one of these disorders is responsible for autistic disorder in your family, then the chance for another person in the family to have the disorder can be specifically predicted.

  In individuals where autistic disorder is caused by a known environmental factor, such as lead poisoning, the risk of autistic disorder occurring in another member of the family is very small.

  In most cases, no specific cause for autistic disorder in an individual is found. A careful evaluation of the family history may enable a genetics professional to estimate the likelihood of autistic disorder recurring in a family member, but it is not always possible to determine an exact figure.

Asperger Disorder
Individuals with Asperger disorder do not have a delay in spoken language development, but can have serious deficits in social and communication skills.

Pervasive Developmental Disorder Not Otherwise Specified (PDD/NOS)
Is a diagnosis often considered for children who show some signs of autistic disorder, but who do not meet the specific diagnostic criteria for the other PDDs.

Rett Disorder
Rett disorder is among the most common genetic cause of profound intellectual and physical disability in girls, occurring more commonly than 1 in 10,000 female births.

Childhood Disintegrative Disorder
Children with childhood disintegrative disorder develop normally for a relatively prolonged period before developing a condition that resembles autistic disorder.