Smith-Magenis Syndrome

By: Aleah Vose

Other Names For This Disoder

  • 17p11.2 microdeletion
  • 17p11.2 microdeletion syndrome
  • Chromosome 17p11.2 deletion syndrome
  • SMS

What causes this disorder?

Smith-Magenis syndrome is caused by a deletion of genetic material from a specific region of chromosome 17. Researchers believe that it is due to the loss of a particular gene in that region called, RAI1. The deletion of this genetic material accidentally happens at the time a child is being conceived, without being inherited from either parent. This shows that SMS is genetic, but not through the family. SMS can occur in anyone. It is more common in people who haven't had a parental chromosome analysis and don't know if their parental chromosomes are normal or not. If parental chromosomes are normal, then the risk for this disease is very low.

Symptoms of SMS

Behavior Problems:

  • Frequent Temper Tantrums and Outbursts
  • Aggression
  • Anxiety
  • Impulsiveness
  • Difficulty Paying Attention


  • Biting
  • Hitting
  • Head Banging
  • Skin Picking

Some symptoms of SMS include self-hugging and a popular behavior called "lick and flip", where a person licks their fingers and flip pages of books. Other symptoms of SMS are having a short stature, abnormal curvature of the spine (scoliosis), no sensitivity to pain and temperature, and sometimes even a hoarse voice. Some people with this disorder have ear abnormalities that can lead to a loss of hearing.

Are there Prenatal Tests for this Disorder?

SMS is a condition that comes from a mutation that occurs on a gene in the early stages of fetal development. Prenatal tests can detect a fetus with SMS but, because SMS is so random and the occurrence can be unpredictable, prenatal testing for this condition is not routinely performed.

What Population is Affected by SMS?

SMS affects 1 in 25,000 people. It is believed though, that many people with the condition have not be diagnosed so it could be closer to 1 in 15,000 people.

Can SMS be Prevented?

SMS cannot be prevented. It occurs randomly and is very unpredictable. There are no known identifiable factors or causes. People who have SMS cannot have children because they have such a large developmental delay. They can't have children but even if they could their children will probably not be affected because this disorder is not familial and it's random occurrences are unpredictable.

What Kind of Medical Assistance does a Child with SMS Need?

A child with SMS needs many treatments and therapies. Treatment can vary due to the intensity of the symptoms. Sometimes, with the proper therapy, people with SMS will grow up and be able to live on their own, but others will rely on support for the rest of their life. A child with SMS has no problems with life expectancy. They should live to around 70.

Treatments for SMS

The goal for treatment of people with SMS is to do it through symptom managment and support management.

  • Speech Therapy
  • Occupational Therapy
  • Physical Therapy
  • Behavioral Therapy
  • Hearing Aids
  • Educative Learning Therapy
  • Music Therapy

Some medications can work as a treatment such as:

  • Melatonin- will regulate the circadian rhythm
  • Risperdal- regulates the violent behavior
  • Amitriptyline- helps promote sleep and treats depression episodes

Are there any Treatments or Cures Coming Soon?

There are now new treatments or cures coming soon. The current status of research is that that people want to improve their knowledge and understanding of SMS so that therapy options can be developed and can improve the quality of life for those who have SMS.


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