Angelman syndrome

Overview

Angelman syndrome is a hereditary disorder characterized by various symptoms including intellectual disability, developmental delays, speech impairment, movement and balance difficulties, and occasional seizures. Individuals with Angelman syndrome often exhibit a cheerful and lively demeanor, frequently expressing smiles and laughter. The condition typically presents with developmental delay that become evident around 6 to 12 months of age, while seizures may begin between 2 and 3 years old. Angelman syndrome is considered rare, affecting approximately 1 in 12,000 to 20,000 individuals.

While there is currently no cure for Angelman syndrome, it is important to note that individuals affected by this condition generally have lifespans that are similar to those without the syndrome. Management of medical, sleep, and developmental concerns is the main emphasis of treatment.

Symptoms

Here are several signs and symptoms commonly associated with Angelman syndrome:

• Impaired intellectual capacity
• Delays in development, such as failure to babble or crawl by 6 to 12 months
• Inability to speak or speaks very few words
• Trouble moving, balancing, or walking
• Problems with feeding or sucking
• Difficulty falling and staying asleep
• Regular giggling and smiling
• Happy and lively personality

The following characteristics may also be present in those with Angelman syndrome:

• Movements become jerky or stiff
• Sticking out of the tongue
• Seizures, which often start between the ages of 2 and 3
• The back of the head appears flat and the size is smaller
• Light colored eyes, hair, and skin
• Issues in sleeping
• Having scoliosis or curving of the spine
• Strange actions, such as walking with arms raised and hands flapping

The majority of newborns with Angelman syndrome don’t exhibit any signs or symptoms. The absence of crawling or babbling between the ages of 6 and 12 months is typically one of the first indicators of Angelman syndrome.

If you observe any developmental delays or notice additional symptoms associated with Angelman syndrome in your child, it is advisable to schedule an appointment with your healthcare provider.

Causes

Angelman syndrome is a genetic disorder caused by a mutation in the UBE3A gene, a ubiquitin protein ligase E3A gene located on chromosome 15. This mutation is primarily responsible for the development of Angelman syndrome.

A missing or defective gene

Your parents give you two sets of genes: a maternal copy (from your mother) and a paternal copy (from your father).

The information in both copies is normally used by your cells, but in a limited number of genes, only one copy is functional.

In the brain, the UBE3A gene normally exclusively expresses activity in the maternal copy. The majority of Angelman syndrome cases involve missing or damaged maternal copies.

When two paternal copies of the gene, rather than one from each parent, are inherited, it can occasionally lead to Angelman syndrome.

Risk factors

Angelman syndrome is considered a rare genetic disorder, and in many cases, the specific cause of genetic abnormalities remains unknown. Most individuals diagnosed with Angelman syndrome do not have a family history of the condition. However, there are rare instances where a parent with Angelman syndrome can pass it down to their child. A family history of the syndrome may increase the likelihood of a baby developing Angelman syndrome, but such occurrences are uncommon.