What is Angelman Syndrome: Causes, Symptoms, Treatment, Risk Factors, Complications, Prevention

Angelman syndrome is a very rare genetic disorder that affects the neurological system. It is a congenital disorder that occurs in one birth among 15000 live births. Being a very rare condition and due to lack of awareness, it is often misdiagnosed as other conditions such as autism and cerebral palsy. It is characterized by delay in development, speech issues, unsteady balance and gait, episodes of seizures etc. A wide range of studies are going on to understand and research more on Angelman syndrome.

Angelman syndrome is not detected at birth. The symptoms of Angelman Syndrome are noticed when the child reaches 6 to 12 months. At first developmental delays are noticed. After a few years when the child is about 2 – 3 years old, seizures are noted. The patients affected by Angelman syndrome, often have a normal life span; however, it is a life-long disorder and requires life-long care. Over a period of time they become slow and develop sleep issues.

What is Angelman Syndrome?

Symptoms of Angelman Syndrome

The most common symptoms of Angelman syndrome are as follows:

  • Developmental delays which includes delay in crawling or babbling. This is noticed at age of 6 to 12 months.
  • Intellectual disability is yet another symptom of Angelman syndrome
  • Minimal speech or lack of speech
  • Difficulty with movement, difficulty while walking, unsteady balance
  • Sudden laughter and frequent smiling
  • Generally a happy and excitable personality.

Most of the above mentioned symptoms of Angelman syndrome are noticed at around the age of 6 to 12 months. There are some other symptoms which are noted after a few years, between 2 to 3 years of age. These commonly include:

  • Seizures
  • Stiffness or sudden jerky movements
  • Physical deformity such as microbrachycephaly i.e. small head size with flatness behind the head
  • Tongue thrusting
  • Hypopigmentation with light pigmentation of hair, skin and eyes
  • Abnormal behaviours such as flapping of hands, lifting of arms while walking etc.

Causes of Angelman Syndrome

Angelman syndrome is a genetic disorder caused by a defect in ubiquitin protein ligase E3A gene (UBE3A) or the chromosome 15 gene. Under normal scenario, genes are inherited from the parents in a pair, with one copy from the mother and one copy from the father. In genes like UBE3A only the maternal side is active. However, in angelman syndrome, the maternal copy of the gene is defective or missing. In some cases of angelman syndrome, both the copies of this gene, is inherited from the father.

Risk Factors of Angelman Syndrome

Being a very rare syndrome, not much is known about the possible risks factors of Angelman syndrome. A large number of studies are going on to learn more about Angelman syndrome. In some cases, it has been seen that there is a family history associated with the syndrome.

Complications of Angelman Syndrome

Angelman syndrome has a number of complications associated with it which includes:

  • Feeding Issues: Feeding issues may arise due to lack of coordination between sucking and swallowing. This can lead to nutritional deficiency. It is advised to follow up with a paediatrician for weight and nutritional management. A high calorie formula is usually recommended in these cases.
  • Hyperactivity: Individuals with Angelman syndrome usually have a short attention span and have a tendency to switch from one activity to another very quickly. In most of the cases, the hyperactivity decreases with aging and usually medications are required for management of the same.
  • Sleep Issues Due to Angelman Syndrome: Most of the patients have abnormal sleep-awake pattern and requires lesser hours of sleep. Sleep related issue improves with aging. Behaviour therapy and medication may be required for regulating the sleep pattern.
  • Scoliosis as a Complication of Angelman Syndrome: Individuals with Angelman syndrome often develop a side to side spinal curvature with abnormal posture.
  • Weight Gain: Obesity may be an issue in older children with Angelman syndrome as they have an increased appetite.

Diagnosis of Angelman Syndrome

Angelman syndrome is diagnosed by the child’s paediatrician or a neurologist based on the signs and symptoms demonstrated by the child. A detailed case history is obtained and the child is observed for symptoms such as behavioural issues etc. Comprehensive blood testing and detailed genetic studies are done for confirming the diagnosis. Genetic tests that are done include the following:

  • DNA Methylation Test to Diagnose Angelman Syndrome: This test is done to study the parental DNA pattern and it helps in screening 3 out of 4 of the known mechanisms of Angelman syndrome.
  • FISH Test/ CGH Test for Diagnosing Angelman Syndrome: A FISH test (fluorescence in situ hybridization) or CGH test (comparative genomic hybridization test) is done for determining the missing portions of the chromosome 15.
  • UBE3A Gene Sequencing Test for Angelman Syndrome: This study is carried out to rule out maternal mutation in UBE3A gene.

Treatment & Management of Angelman Syndrome

Angelman syndrome as such does not have a definite treatment. At present the treatment modality is focused on management of the associated medical and developmental issues. Based on the extent of the condition and the age of the patient, the following treatment plan may be considered:

  • Medications for Managing Angelman Syndrome: Anti-seizure medications may be used for management of seizures in patients with angelman syndrome.
  • Physical Therapy and Exercises for Angelman Syndrome: Manipulation by a trained physical therapist ay help is management of walking difficulties and movement issues. Certain home exercises may also be recommended for the same, which is usually carried out with assistance.
  • Communication Therapy to Deal with Angelman Syndrome: Sign languages and picture communication may be taught to the children and the parents for improving communication skills.
  • Behaviour Therapy for Managing Angelman Syndrome: This is usually done for management of hyperactivity and short attention span.

Prevention of Angelman Syndrome

A link has been found between family history and incidence of angelman syndrome. If there is a known family history of angelman syndrome or if one child has angelman syndrome then before planning any future pregnancies one must consult a doctor. It is recommended to consult a genetic counsellor before planning for a pregnancy in case of known history of any genetic diseases to avoid complications.


Angelman syndrome is a very rare complex genetic disease caused by defect or mutation in the UBE3A gene or chromosome 15 genes. This condition usually goes undiagnosed at birth. The symptoms start to surface at age of 6 to 12 months as developmental delays, speech impairment, learning disabilities, difficulty with movement and unsteady balance and gait. Quite often the condition is confused with autism and other congenital issues due to lack of information and medically relevant data and hence one must consult an experienced doctor for the diagnosis. Individuals with Angelman syndrome are often very happy, hyper excited children, characterized by short attention span and frequent laughing and smiling. The condition is usually diagnosed once the patient starts showing signs and symptoms of Angelman syndrome. A series of blood work and genetic tests are done to arrive at the final diagnosis. There is no definite treatment modality to cure the condition. A large number of research and studies are being carried out to understand this condition better and more accurately.

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:June 12, 2017

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