Related Disorders
PubMed Article on the Genetic Disorders Associated with Symptoms of Autism
Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS or PDD)- PDD is defined in the DSM-IV as "presentations that do not meet the criteria for Autistic Disorder because of late age at onset, atypical symptomology, or subthreshold symptomology, or all of these." It's sort of a "catch-all" category. Some symptoms of Autistic Disorder are present but not enough for the diagnosis (See DSM-IV). Many parents breathe a sigh of relief when told, "Your child is not autistic, he just has PDD." Perhaps there is some comfort in this, in that the symptoms may not be as severe but please read Dr. Bernard Rimland's article: Plain Talk about PDD and the Diagnosis of Autism, before you breathe too easily. PDD indicates problems with the child's socialization or communication or repetitive behaviors or a combination of some of these. For more information on PDD please visit: Autism Speaks PDD-NOS Page and/or the Emory Autism Center's discussion on What is the Difference Between Autism and PDD-NOS and/or Information on PDD-NOS.
Rett's Disorder - The DSM-IV begins the diagnostic criteria for Rett's Syndrome with signs of normalcy: "apparently normal prenatal and perinatal development, apparently normal psychomotor development through the first five months after birth, and normal head circumference at birth." If this were a movie, you would hear ominous background music about now. Rett's Disorder is one of the more tragic disorders because of this period of "normalcy". I once watched a videotape of home movies shot by loving parents of a girl with Rett's Disorder. Such a beautiful child and then, at around five months, the symptoms began, almost imperceptively at first. The DSM-IV continues: "deceleration of head growth between 5 and 48 months; loss of previously acquired purposeful hand skills between 5 and 30 months with the subsequent development of stereotypical hand movements (e.g., hand-wringing or hand washing); loss of social engagement early in the course (although often social interaction develops later); appearance of poorly coordinated gait or trunk movements; (and) severely impaired expressive and receptive language development with severe psychomotor retardation." Rett's Disorder occurs almost exclusively in females. For more information on Rett's Disorder please visit: The International Rett Syndrome Association and/or The OMIM Rett Syndrome Entry and/or Our Rett Syndrome Page and/or Family Village Rett Syndrome Page. For information on the gene that causes Rett Syndrome, visit: Business Wire Article.
Childhood Disintegrative Disorder - This condition has also been called: Heller's syndrome, dementia infantilis, or disintegrative psychosis. The DSM-IV starts the diagnostic criteria with at least a two year period of normal development in all areas. However, this is followed by a "clinically significant loss of previously acquired skills (before age 10 years) in at least two of the following areas: expressive or receptive language, social skills or adaptive behavior, bowel or bladder control, play, or motor skills." In addition, the DSM-IV looks for: "Abnormalities of functioning in at least two of the following areas: qualitative impairment in social interaction, qualitative impairments in communication, (and/or) restricted, repetitive, and stereotyped patterns of behavior, interests, and activities, including stereotypies and mannerisms." The DSM-IV also states that the disorder is not better accounted for by another Pervasive Developmental Disorder or by Schizophrenia. The key difference between this disorder and autism is the period of normal development for at least the first two years of life (and perhaps up to age 10). For more information on Childhood Disintegrative Disorder please visit: Mayo Clinic CDD Web Site and/or the Oakland Chapter of the Autism Society of America CDD Web Site.
Asperger's Disorder - Asperger's Disorder (also known as Asperger Syndrome) is "a neurobiological disorder named for a Viennese physician, Hans Asperger, who in 1944 published a paper which described a pattern of behaviors in several young boys who had normal intelligence and language development, but who also exhibited autistic-like behaviors and marked deficiencies in social and communication skills." Asperger's Disorder is an autism spectrum disorder which is diagnosed by using a portion of the DSM-IV criteria for Autistic Disorder. A child or adult with Asperger's Disorder will meet the DSM-IV criteria for Autistic Disorder in the "impaired social interaction" and "restricted repetitive and stereotyped patterns of behavior, interests, and activities" categories. However, there will be "no clinically significant general delay in language (e.g., single words used by age 2 years, communicative phrases used by age 3 years)" and there will be "no clinically significant delay in cognitive development or in the development of age-appropriate self-help skills, adaptive behavior (other than social interaction), and curiosity about the environment in childhood." While their vocabulary may be age-appropriate or higher, their social use of language (pragmatics) will typically be deficient. Children with Asperger's Disorder may not be diagnosed until well into their school years. This probably is due to the unimpaired cognition and less-impaired language skills they possess. Also, school is where the difficulty with social skills would most likely be evident. Some persons with Asperger's Disorder come across as merely eccentric or odd. Persons with Asperger's Disorder may be preoccupied with and may only want to talk about a particular area of interest to them. They may have difficulty switching from one activity or topic to another and may prefer sameness. They often have obsessive routines and may demand that others comply with them as well. Persons with Asperger's Disorder may seem to lack common sense, may not be able to pick up on nonverbal cues (body language), and may ignore appropriate personal space "rules." As with the other autism spectrum disorders, they may be overly sensitive to sounds, tastes, smells, and sights. To learn more about Asperger's Disorder, visit: Online Asperger Syndrome Information and Support and/or Aspen of America, Inc. and/or Tony Attwood's Web Site.
Nonverbal Language Disorder - NLD is also known as Nonverbal Learning Disability. For more info: http://www.nldontheweb.org/, http://www.nldline.com/, and/or http://www.udel.edu/bkirby/asperger/NLD_SueThompson.html.
Fragile X Syndrome - Symptoms of Fragile X Syndrome include: mental impairment (ranging from learning disabilities to mental retardation), attention deficit and hyperactivity, anxiety and unstable mood, and autistic-like behaviors. Characteristic physical features may include: long face, large ears, flat feet, and hyperextensible joints, especially fingers. Males are typically more severely affected than females. Emotional and behavioral problems are common in both sexes. Fragile X Syndrome is caused by a chromosomal abnormality. In Fragile X Syndrome, a portion of the X chromosome is somewhat longer than normal. This extra length causes one of the genes to be "switched off" and it does not produce a protein that is necessary for normal development. Females, who have two X chromosomes, have at least one unaffected X chromosome to counteract this "switching off." Genetic testing is available to diagnose Fragile X Syndrome. To learn more about Fragile X Syndrome, visit: FRAXA Research Foundation and/or OMIM Fragile X Entry. For some recent research findings on Fragile X, see: the ScienceCentralNews article, Noisy Brains
Williams Syndrome - Williams Syndrome Association and/or OMIM Williams Syndrome Entry.
Landau-Kleffner Syndrome - Landau-Kleffner Syndrome and/or Teresa Binstock on Landau-Kleffner and the Herpes Simplex Virus.
Prader-Willi Syndrome - Prader-Willi Syndrome Association - USA
Angelman Syndrome - Angelman Syndrome and/or OMIM Angelman Syndrome Entry.
Tuberous Sclerosis - OMIM Tuberous Sclerosis Entry and/or Tuberous Sclerosis Alliance Link
Moebius Syndrome - Moebius and I Support Network - Bob Emery's great site.
Kabuki Syndrome - Kabuki and Autistic-type Behaviors
Isodicentric 15 - "Isodicentric 15 [abbreviated idic(15)] is one of a group of genetic conditions known as chromosome abnormalities. People with idic(15) are typically born with 47 chromosomes in each of their body cells, instead of the usual 46 found in most people. The extra chromosome is referred to as an "isodicentric 15", an "inverted duplication 15", or a "supernumerary marker". In people with idic(15), the extra chromosome is made up of a piece of chromosome number 15 which has been duplicated end-to-end like a mirror image." (From the IDEAS web site). It is the presence of this extra genetic material that is thought to account for the symptoms of autism seen in some people with idic(15).
For more information on idic (15), visit the following web site: IDEAS
Fetal Alcohol Syndrome - Fetal Alcohol Syndrome Community Resource Center and/or FAS/FAE Student Checklist.
Mental Retardation - On intelligence tests, many persons with autism will score within the mentally retarded range. The DSM-IV reports that "approximately 75% of children with Autistic Disorder (autism) function at a (mentally) retarded level." While this bluntness may work on the printed page of a manual, the reality is that persons with autism are not really set up to do well on standardized tests. In order to test a child one needs to communicate with the child (a weakness for children with autism), to interact socially (another area of weakness for children with autism), and the child's behavior needs to not interfere with the testing (oops - a third strike for many children with autism). IQ tests are notoriously unreliable with children with autism and should not be used to limit what we teach them or expect of them. Now on the other hand, many children with mental retardation (particularly at the lower ends of the spectrum) may exhibit symptoms which are similar to autism. They may have social interaction problems, communication problems, and may make odd movements (stereotypies). To learn more about mental retardation, visit: The ARC Home Page