Angelman Syndrome

Angelman syndrome is a complex genetic condition that leads to developmental and neurological challenges, including significant speech impairments and difficulties with walking and balance (ataxia).

What Is Angelman Syndrome?

Angelman syndrome is a rare and complex genetic disorder that primarily affects the nervous system. It's caused by changes in a gene called UBE3A, which plays a key role in brain development. These changes happen during fetal development and can affect movement, communication, and behavior.

What Does the Nervous System Do?

Your nervous system is like your body’s control center. It helps you move, think, react, and interact with the world around you. When something disrupts its development—like in Angelman syndrome—it can lead to a range of challenges.

Key Characteristics of Angelman Syndrome

Symptoms can vary from person to person, but common features include:

• Developmental delays, often noticeable by 6 to 12 months of age 
• Intellectual disability 
• Little or no speech 
• Movement and balance issues (ataxia) 
• Seizures 

Many children with Angelman syndrome also have a uniquely joyful demeanor. They often smile, laugh frequently, and flap their hands when excited.

A Brief History

The syndrome was first described in 1965 by Dr. Harry Angelman, an English physician who noticed a pattern of similar symptoms in a group of children.

Who Can Be Affected?

Angelman syndrome can develop in any child, regardless of family history. Most cases are not inherited—they result from a spontaneous mutation in the UBE3A gene.

How Common Is It?

Angelman syndrome is quite rare, affecting about 1 in every 12,000 to 20,000 people worldwide.

Is Angelman Syndrome Related to Autism?

Although Angelman syndrome shares some features with autism—like delayed speech and development—they are distinct conditions. Angelman is not on the autism spectrum.

Signs and Symptoms

Symptoms vary with age and individual. Here are some of the most common:

General Symptoms

• Severe speech delays (many are nonverbal or use only a few words) 
• Learning and intellectual disabilities 
• Movement difficulties (like clumsiness or wide-based walking) 
• Seizures 
• Ataxia (trouble with coordination) 

Facial Features

Some individuals may have:

• A small, broad skull (brachycephaly) 
• A large tongue (macroglossia) that may stick out 
• A small head (microcephaly) 
• A prominent lower jaw 
• Wide mouth and spaced-out teeth 

Behavioral Traits in Children

Children with Angelman syndrome often:

• Are unusually happy and excitable 
• Laugh and smile frequently 
• Flap their hands when excited 
• Have sleep difficulties 
• Show a fascination with water 
• Have short attention spans 

These behaviors may change with age—excitability may lessen and sleep can improve.

What Causes Angelman Syndrome?

The condition is tied to the UBE3A gene, which is vital for brain development. Everyone inherits one copy of this gene from each parent, but in specific brain regions, only the mother’s copy is active. If that maternal copy is missing or not working due to a mutation or deletion, the brain doesn’t receive the gene’s necessary function—leading to Angelman syndrome.

Causes by Percentage:

• ~70%: Maternal UBE3A gene is missing or inactive 
• ~11%: Structural issues with the UBE3A gene 
• ~10–15%: Cause is unknown or involves other genetic changes 

Diagnosing Angelman Syndrome

Angelman syndrome is often diagnosed between 1 and 4 years of age, when developmental delays become more apparent. But diagnosis can sometimes happen earlier—even before birth.

Common Diagnostic Tools:

• Genetic testing (to identify changes in UBE3A) 
• EEG (to detect characteristic brain wave patterns or seizures) 
• Sleep studies (to assess sleep issues) 
• Prenatal screening like NIPS (Noninvasive Prenatal Screening) can detect potential genetic abnormalities 

Because symptoms overlap with other conditions (like autism, cerebral palsy, or Prader-Willi syndrome), genetic testing is the only way to confirm the diagnosis.

How Is Angelman Syndrome Treated?

There is currently no cure, but treatment focuses on managing symptoms and supporting development. Early intervention can make a big difference.

Treatment Approaches:

• Anti-seizure medications 
• Physical and occupational therapy to improve movement and coordination 
• Speech and communication therapy, including sign language or communication devices 
• Behavioral therapy for sleep issues or attention difficulties 
• Nutritional support and gastrointestinal care if needed 

Care typically involves a team of specialists—pediatricians, neurologists, therapists, and more.

Living with Angelman Syndrome

Every child is different. While Angelman syndrome brings lifelong challenges, many individuals live a full life with proper care and support.

What to Expect:

• Developmental progress is possible, especially with therapy 
• Behavioral traits may change or improve with age 
• Most people with Angelman syndrome have a normal life expectancy 
• Constant care and support are often needed throughout life 

Supporting Your Child:

• Follow all therapy and medication plans 
• Stay on top of regular checkups 
• Explore tools to aid communication 
• Ask your provider about local and online support groups 

FAQs

Can it be prevented? In most cases, no—Angelman syndrome happens due to a random mutation. However, genetic counseling may be helpful for families with a known history of related conditions. Will my child develop normally? Children with Angelman syndrome experience developmental delays, but early therapy and consistent care can help them reach their potential. Is there a community I can connect with? Absolutely. Many support groups, both online and local, offer resources and a sense of community for families.

A Final Note

If your child has been diagnosed with Angelman syndrome, you’re not alone. It’s okay to feel overwhelmed—but there’s help, support, and hope. With the right care, children with Angelman syndrome can thrive, grow, and bring joy to those around them.