Key Facts

If a person has a diagnosis of Smith-Magenis syndrome it does not mean they will show all behaviours associated with the syndrome and it is extremely important to remember that everyone with Smith-Magenis syndrome is an individual.

Most people with Smith-Magenis syndrome have an intellectual disability, typically in the moderate intellectual disability range

Individuals with Smith-Magenis syndrome have been described as having an “endearing” and affectionate personality and a strong sense of humour

Sleep difficulties begin in childhood and carry on into adulthood and may change over time

Repetitive and stereotyped behaviours such as hand flapping, spinning/twirling objects or body rocking are commonly reported in Smith-Magenis syndrome. 

’Attachment’ to particular people (shown by continually asking to see, speak to or contact a particular favourite person) is very common in Smith-Magenis syndrome compared to other genetic syndromes

Challenging behaviour including self-injury and aggression frequently occurs in Smith-Magenis syndrome with prevalence rates between 70-96% for self-injury and 70-88% for aggression.

Individuals with Smith-Magenis syndrome are more likely to display behaviours related to physical discomfort and pain

Impulsivity is more common in individuals with Smith-Magenis syndrome than in others with an intellectual disability without this syndrome and when compared to a range of other syndromes

Emotional control may be impaired in Smith-Magenis syndrome, so there may be problems controlling emotional responses which may result in temper outbursts.

Communication impairments are reported in individuals with Smith-Magenis syndrome with weaknesses in expressive language compared to receptive language

Individuals with Smith-Magenis syndrome have been found to have relative strengths in long-term memory, computer skills, perceptual skills and socialisation

Download a summary of common behavioural characteristics in Smith-Magenis syndrome here

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