Focus on Rare Disease – Angelman Syndrome

1. What is Angelman Syndrome?

Angelman Syndrome is also known as Angel Syndrome and Happy Puppet Syndrome. Angelman Syndrome is a disorder that affects neurodevelopment due to a genetic abnormality. It is characterized by mental retardation, language disorders, and seizures.

Angelman Syndrome is an extremely rare disorder, with a worldwide incidence of about 1 in 50,000 to 1 in 10,000 cases. Individuals with Angelman Syndrome are often small in stature and laugh frequently, and have a happy and excitable personality.

British pediatrician Harry Angelman first discovered and systematically described the disorder in 1965, which gave it its name.

2. Causes of Angelman Syndrome

Angelman syndrome is a genetic disorder caused by an abnormality in the ubiquitin-protein ligase 3A (UBE3A) gene in the region of chromosome 15q11-13.

Typically, people receive pairs of genes from their parents, one from their mother (maternal genes) and the other from their father (paternal genes). And biologists in the 1980s discovered that while parents together provide 50% of the genetic material to their offspring, cells normally use information from both portions of the inherited material to express genes. However, in the chromosome 15q11-13 region where the UBE3A gene is located, the maternal gene would be normally expressed in the offspring, while the paternal gene would be silenced. Therefore, if the maternal portion of the gene is inherited with damage, deletion, or mutation, it can lead to Angelman Syndrome.

3. Clinical manifestations of Angelman Syndrome

Typically, Angelman Syndrome has the following typical clinical manifestations:

· Developmental delay: Patients experience delays in motor and language development, including an inability to crawl or babble at 6 to 12 months of age.

· Language disorders: patients often fail to develop fluent language skills and may be able to communicate only through nonverbal gestures, facial expressions, and intonation.

· Dyspraxia: Patients may have impairments in limb movement, including ataxia, uncoordinated gait, and involuntary hand and limb movements or shaking.

· Narcoleptic tendencies: patients often exhibit a preference for sleep and extreme sensitivity to the environment.

· Pleasurable Laughter Disorder Tendencies: patients typically exhibit frequent and unexplained happiness and laughter.

· Inattention: Patients with Angelman Syndrome often have difficulty maintaining focus and are easily distracted.

It should be noted that the degree of several of these clinical manifestations will vary from patient to patient due to differences in age, and symptoms may vary.

4. Treatment and Care

The life expectancy of patients with Angelman Syndrome is usually close to the average. Unfortunately, there is no effective way to completely cure it. We can only prevent Angelman Syndrome through, for example, genetic planning. For children with the condition, caregivers are needed to carefully accompany them to avoid accidents. If necessary, caregivers need to know how to handle seizures, such as moving the patient to a flat area to prevent falls. In the future, as science advances, perhaps we will find a cure for Angelman Syndrome.