Angelman Syndrome Definition, Reason, Symptoms, Treatment & Prevention

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Angelman Syndrome Definition, Reason, Symptoms, Treatment & Prevention

Definition

Angelman syndrome is a term used to describe a genetic condition that affects the nervous system and causes physical and intellectual disability. It is estimated that this condition occurs in 1 out of every 15,000 live births.

Unfortunately, Angelman syndrome is often misdiagnosed as cerebral palsy or autism. This is due to a lack of awareness of this disease.

People with Angelman syndrome have a life expectancy that is more or less the same as the normal population. However, people with this syndrome need lifelong support for themselves.

Angelman Syndrome Symptoms

Based on the consensus diagnostic criteria for Angelman syndrome, there are several symptoms that can be found, including:

  • Consistency

    • Functionally severe developmental delay
    • Movement or balance disorders, generally in the form of ataxia or trembling of the limbs during movement
    • Unique behavior, such as laughing or smiling frequently, happy demeanor, easily excitable nature, frequently waving or flapping hands, hypermotor
    • Speech disorders, in which the use of words is absent or very minimal

  • Frequent (found in almost 80 percent of cases)

    • Growth in head circumference is delayed and inappropriate, often leading to microcephaly by the age of 2 years
    • Seizures, usually at the age of under 3 years
    • Abnormalities in EEG examination

  • Associated (found in 20–80 percent of cases)

    • Flat or grooved occiput
    • Tongue protruding may be accompanied by difficulty sucking or swallowing
    • Difficulty eating or breastfeeding
    • Prognathia
    • Wide mouth, spaced between teeth
    • Frequent salivation
    • Strabismus
    • Hypopigmentation of the skin, hair, and eye color that is lighter than other family members
    • Increased sensitivity to heat
    • Abnormal sleep cycles, reduced need for sleep
    • Obesity
    • Constipation
    • Scoliosis

Angelman Syndrome Reason

Angelman syndrome is caused by an abnormal function of the UBE3A gene on chromosome 15. Normally, everyone has two copies of the UBE3A gene from each parent. Both copies of this gene are active in various body tissues. But in the human brain, only the mother’s copy of the UBE3A gene (maternal copy) is active. If the maternal copy is lost, for example due to a genetic mutation or chromosomal change, then there will be no active copy of the UBE3A gene in the brain. This is what causes the symptoms of Angelman syndrome.

Various causes of problems that lead to the loss of maternal copies of the UBE3A gene, namely:

  • Inactivation or deletion of the maternal copy of the UBE3A gene occurs in approximately 70 percent of cases
  • Mutations of the maternal copy of the UBE3A gene occur in approximately 11 percent of cases
  • Paternal Uniparental Disomy, in which a person has two copies of the paternal gene (normally one paternal gene and one maternal gene), occurs in approximately 3 percent of cases
  • In 10–15 percent of cases, the cause of Angelman syndrome is unknown.

In general, the genetic disorder that causes Angelman syndrome is not inherited. These genetic disorders generally occur randomly during the formation of reproductive cells (eggs and sperm cells) or during early fetal development.

Diagnosis

To determine the diagnosis of Angelman syndrome, in 2006 a consensus was published that established the following criteria:

  • Developmental history and laboratory findings in Angelman syndrome:
    • History of normal pregnancy and delivery, with normal head circumference and no major congenital abnormalities. There may be difficulty in suckling or eating as a neonate or toddler.
    • Developmental abnormalities that generally appear at the age of 6–12 months. There may be an imbalance in limb movement and smiling habits
    • Late development, but always progress (no loss of skills)
    • Laboratory tests for normal metabolic, blood, and chemical function
    • Normal brain structures on an MRI or CT scan
  • Clinical symptoms of Angelman’s syndrome: will be discussed in more detail in the next point

In addition to the above consensus, diagnostic tests can be carried out by carrying out genetic tests. Various tests that can be performed include chromosomal analysis, FISH ( fluorescence in situ hybridization ), DNA methylation, and UBE3A gene mutation analysis.

Angelman Syndrome Treatment

This condition is caused by a genetic disorder, so it cannot be cured. The treatment offered will depend on the symptoms that arise, for example:

  • taking anti-seizure medication if you have seizures
  • physiotherapy to help with posture, movement and balance
  • communication therapy, to develop non-verbal communication

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