There are a number of disorders that are related to Autism Spectrum Disorder and may have several similar symptoms. Differentiating between the disorders can be difficult, although they all have distinct traits. Compounding this confusion is the fact that many of these disorders are comorbid, meaning one person can have two or more of both disorders at the same time. Here are a few of the disorders related to Autism Spectrum Disorder along with the unique characteristics of each.

Williams Syndrome

Williams Syndrome is genetic and is distinct from autism in that it involves a mild form of mental retardation. It is a very rare disorder caused by the absence of some of the DNA material from chromosome 7. Williams Syndrome is often mistaken for Autism because they have similar symptoms such as delayed speech, motor skill development problems, and sensitivity to noise. It is distinct from Autism because of the physical issues that accompany Williams Syndrome, such as heart problems and high blood pressure. People with Williams Syndrome are usually very social, also setting them apart from those with Autism. Physical traits associated with Williams Syndrome include an almost fairy-like appearance, with rounded ears, wide mouths, and narrow faces. 

Tardive Dyskinesia 

Tardive Dyskinesia is a disorder that can result from long-term use of certain antipsychotic medications. The disorder can manifest months or even years after the use of the medication. It often presents in the form of uncontrollable, repetitive jerking movements of the neck, face and tongue. Anyone taking antipsychotics can develop Tardive Dyskinesia, but higher-risk patients include the elderly, women, patients with diabetes, and patients with other mental disorders. Supplements are used to treat and/or prevent TD, although some symptoms and complications may not be curable. If the medication that caused TD is still being taken, the doctor should be notified so they can prescribe how to safely adjust, discontinue or switch medications. 

Prader-Willi Syndrome

Prader-Willi Syndrome symptoms include an obsession with food, low muscle tone, short height, and impulsive eating. Most people with Prader-Willi Syndrome also have a mild form of mental retardation. Due to their food obsession, most with PWS are overweight or obese and suffer from related complications. There is no known cause of PWS, although some believe it is due to a missing portion of chromosome 15 from the paternal side of the family (another disorder called Angelman’s Syndrome is associated with a missing portion of chromosome 15 from the maternal side). People with Prader-Willi Syndrome often do not respond to medication and the best course of treatment is behavior modification. It can be confused with Autism because the two disorders share the symptoms of trouble feeding in infancy, sleep issues, temper tantrums, learning disabilities, and speech delays. 

It can be difficult for parents and physicians to differentiate between these disorders (along with many others) and Autism Spectrum Disorder, especially since some suffer from both conditions at the same time. Observations of children and the full medical history of the child and parents can be of great help to doctors in finding distinctive characteristics and distinguishing between disorders.