Angelman syndrome

Author: Brian Wu PhD. MD Candidate, Keck School of Medicine, Los Angeles, USA; Chief Editor: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, February 2016.


What is Angelman syndrome?

Angelman syndrome is a rare neurological disorder which occurs in 1 out of every 15,000 births and in the past, was mistaken for other disorders like cerebral palsy or autism. It is marked by a complex array of symptoms.

 It was named for Dr. Harry Angelman, who first described the disorder in 1965.

Who gets Angelman syndrome?

Angelman syndrome is rare:

  • Most people with Angelman syndrome have no family history of it
  • In small percentage of cases, the syndrome can be inherited from a parent
  • There are no racial or sexual preferences noted in the medical literature

What causes Angelman syndrome?

Angelman syndrome is genetic in origin:

  • Genes UBE3A, HERC2, OCA2 and SNPRN are most often involved
  • OCA2 is responsible for hypopigmentation   
  • The exact cause is unknown in 10–15% of cases
  • Genetic changes can be random, ie, without a family history of the disorder

What are the clinical features of Angelman syndrome?

Cutaneous features of Angelman syndrome include:

  • Hypopigmented skin
  • Ocular cutaneous albinism
  • Deficiency of choroidal pigment
  • Incomplete melanisation of melanosomes
  • Light blue iris
  • Decrease in retinal pigment
  • Low hair bulb tyrosinase activity

Noncutaneous features of Angelman syndrome include seizures, developmental delays, limited or lack of speech, mobility disorders, increase in smiling, a happy, excitable personality, hand flapping, abnormal sleep cycles and microcephaly.

How is Angelman syndrome treated?

There is no cure for Angelman syndrome. Lifelong care is needed and treatment focuses on managing symptoms. It can include:

  • Anti-seizure medications (including sodium valproate alone or with clonazepam or other benzodiazepine)
  • Communication therapy to instruct children to use sign language or pictures
  • Behaviour therapy to help treat short attention spans and hyperactivity

What is the outcome for Angelman syndrome?

Despite the many limitations, the life expectancy of patients with Angelman syndrome is normal.  Often, patients will become less excitable as they age and they outgrow sleep cycle abnormalities. 

 

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