What is Smith-Magenis syndrome?

Smith-Magenis syndrome (SMS) is a complex developmental disorder that affects multiple organ systems of the body. The disorder is characterized by a pattern of abnormalities that are present at birth (congenital) as well as behavioral and cognitive problems.

How common is Smith-Magenis syndrome?

Smith-Magenis syndrome affects at least 1 in 25,000 individuals worldwide. However, researchers believe that many people with this condition are not diagnosed, so the true prevalence may be closer to 1 in 15,000 individuals.

Please discuss with your doctor for further information.


What are the symptoms of Smith-Magenis syndrome?

The common symptoms of Smith-Magenis syndrome are:

  • Distinct facial features
  • Certain skeletal malformations
  • Variable intellectual disability
  • Delay in speech and attaining motor skills
  • Inability to sleep adequately
  • Tendency towards self harm and other attention seeking behaviors

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you or your loved one has any signs or symptoms listed above or has any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes Smith-Magenis syndrome?

The main cause of Smith-Magenis syndrome is a missing short arm of chromosome 17. This constitutes for about 90% of the cases of Smith-Magenis syndrome.

This missing portion of the chromosome contains the RAI1 gene which is responsible for growth and development of an individual.

The main reason for the chromosome that is missing or deleted is not yet known but in maximum cases this is spontaneous and is not related to any other cause.

Risk factors

What increases my risk for Smith-Magenis syndrome?

Please consult with your doctor for further information.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is Smith-Magenis syndrome diagnosed?

A diagnosis of Smith-Magenis syndrome is based upon identification of characteristic symptoms, a detailed patient and family history, a thorough clinical evaluation and a variety of specialized genetic tests. The diagnosis of SMS is confirmed when deletion 17p11.2 (cytogenetic analysis or microarray) or RAI1 gene mutation is identified.

How is Smith-Magenis syndrome treated?

The treatment for Smith-Magenis syndrome requires a multidisciplinary effort from a team of specialists which will include pediatricians, neurologists, speech and language specialists, psychiatrists and psychologists, who will work together and formulate a treatment plan for the patient.

Genetic counseling may also be of benefit for the patient and the family and will help in the course of treatment. Other than supportive and symptomatic, there is no other clear cut treatment for Smith-Magenis syndrome. Early diagnosis and treatment is essential for the child to be as independent as possible.

Smith-Magenis syndrome child will require special education with speech and language therapy, physical therapy and occupational therapy for making the child independent. Sensory integration therapy will also be of benefit in children with Smith-Magenis syndrome to allow them to respond better to stimulus which is extremely poor in cases of Smith-Magenis syndrome.

To treat behavioral and attention seeking problems in children with Smith-Magenis syndrome, medications may be used. For difficulties in feeding, consultation with a GI specialist in coordination with the pediatrician will be of great value. To control seizures, again anticonvulsants are available which will help control seizures.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Smith-Magenis syndrome?

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: February 22, 2018 | Last Modified: February 22, 2018

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