How is Rett Syndrome Different from Autism?

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Genetic and Gender Differences

Both autism and Rett Syndrome appear to have a genetic component. Autism runs in families and it is not uncommon for parents to have more than one child with some of the social, communication or sensory characteristics. Autism affects males much more frequently than females. Rett syndrome, on the other hand, appears to be caused by a genetic mutation on the X chromosome and it only affects girls. It is very rare for Rett’s to be passed down to the next generation. It appears to occur spontaneously and randomly- making Rett syndrome different from autism.

Differences in Severity and Progression

The type and severity of autistic characteristics can vary a great deal. Children with autism may be very intelligent or have severe cognitive impairments. Social and communication challenges and sensory sensitivities may be evident in the baby with autism who may avoid eye contact and dislike touch. Children with Rett syndrome, on the other hand, develop normally during at least the first five months and then experience deterioration in motor skills, social interactions and coordination. Although children with autism may demonstrate repetitive stereotypic movements, children with Rett’s always lose purposeful hand skills, engage in stereotypic hand movements and have cognitive impairment-making Rett syndrome different from autism.

Physical and Health Differences

Individuals with autism can expect to have a normal life expectancy. However, they may experience anxiety and depression that impact overall health or increase the chance of suicide. Children with autism or Rett syndrome may choose to eat a very limited diet due to sensory sensitivities-affecting their nutritional status.

Children with Rett syndrome often develop feeding problems including impaired abilities to chew, swallow and feed themselves. In addition, children with Rett’s experience progressive muscle wasting, decreased mobility, balance problems, seizures and breath holding episodes that affect their health.

Communication and Language Skills

Children with high functioning autism-sometimes called “Asperger’s syndrome” may develop very good language and reading skills at an early age. However, communication is impacted by difficulties understanding abstract language such as idioms and reading social cues. They tend to interpret words literally and struggle to understand what is called “theory of mind”. Theory of mind enables a person to understand the mental processes of others. A child with autism, for example, may expect his or her mother to know what happened at school even though she was not there.

Children with Rett syndrome have cognitive impairments that interfere with understanding and speaking words. Muscle weakness and decreased coordination of the oral motor (mouth) muscles also impact abilities to speak. These severe communication challenges often make Rett syndrome different from autism. However, children with either low functioning autism or Rett’s may benefit from use of communication boards that require touching pictures of easily identifiable objects in the child’s life.


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