Angelman Syndrome: Causes, Symptoms, Diagnosis & Treatment

Learning that you or your loved one may have Angelman syndrome can feel terrifying. It’s natural to have questions and concerns, especially when facing something unfamiliar. Angelman syndrome is a rare genetic condition that affects the brain and development, often showing up in early childhood. 

While it can bring challenges, many people with Angelman syndrome lead happy and fulfilling lives with the right care and support. Understanding the symptoms and available treatments can help you feel more informed and prepared.

What is Angelman Syndrome?

Angelman syndrome is a rare neurogenetic disorder that affects the nervous system, leading to developmental delays, speech impairments, and movement challenges. Children with this condition often have a cheerful disposition, smiling and laughing frequently. 

Despite challenges, many individuals live full lives with the right support. While there's no cure, early intervention and consistent therapies help manage the symptoms and improve quality of life.

Who Does Angelman Syndrome Affect?

Angelman syndrome can affect individuals of any background. It typically presents in early infancy, often between 6 and 12 months, when developmental milestones such as crawling or babbling may be delayed. Both boys and girls are affected equally. 

While the condition itself is not inherited in most cases, it stems from a genetic change that occurs during development in the womb. 

Children with Angelman syndrome usually have a kind, excitable temperament and enjoy interaction, even if they struggle with speech and coordination. As a parent or caregiver, recognising early signs and seeking a diagnosis is key to accessing timely support.

How Common is Angelman Syndrome?

Angelman syndrome is considered rare, affecting approximately 1 in 12,000 to 20,000 live births. Because the signs can resemble other conditions like autism or cerebral palsy, it might be underdiagnosed or misdiagnosed in some cases.

Is Angelman Syndrome On The Autism Spectrum?

While some behaviors of Angelman syndrome may resemble those seen in autism spectrum disorder (such as limited speech or hand-flapping), the two are distinct conditions. Angelman syndrome is caused by specific genetic factors and is not classified as part of the autism spectrum.

Angelman Syndrome Symptoms

Angelman Syndrome symptoms can vary from person to person, but certain features are commonly seen across individuals. These often become noticeable during early childhood.

Common Symptoms Of Angelman Syndrome

You may notice some developmental and behavioural traits early on.

• Developmental delays such as late crawling, walking, or talking.
• Minimal or no speech—many children may use gestures or devices to communicate.
• Balance and coordination issues, making walking appear stiff or unstable.
• Frequent smiling and laughter, often triggered by excitement.
• Hyperactivity or short attention spans, though this may ease with age.
• Seizures, often beginning around 2-3 years of age.
• Sleep difficulties, including trouble falling or staying asleep.

Facial Features Of Angelman Syndrome

Children with Angelman syndrome may share some distinctive facial traits.

• Wide mouth with prominent spacing between teeth.
• Flat back of the head (brachycephaly) and small head size (microcephaly).
• Large tongue, which may stick out frequently.
• Prominent chin and jawline, noticeable in adolescence or adulthood.
• Light skin, hair, and eyes due to lower pigment levels.

Symptoms Of Angelman Syndrome Specific To Children

Some symptoms are particularly noticeable in children with this condition.

• Delayed milestones like sitting or walking independently.
• Feeding difficulties in infancy, including poor sucking reflex.
• Frequent drooling or difficulty swallowing.
• Hand-flapping and uplifted arms during movement.
• High levels of activity, but with limited attention span.

Causes Of Angelman Syndrome

The Angelman Syndrome causes stem from a genetic issue.

Angelman syndrome occurs when there is a deletion or mutation in the UBE3A gene on chromosome 15. Normally, this gene is active in the brain only from the mother’s side. If the maternal copy is missing or altered, the brain lacks the enzyme necessary for normal neurological function.

• In most cases, the issue happens randomly during development.
• A small number of cases involve inherited genetic mutations.
• Sometimes, two copies of the paternal gene are inherited (called paternal uniparental disomy).
• In rare situations, the cause is unknown but still affects UBE3A function.

Risk Factors

Angelman syndrome typically occurs due to spontaneous genetic changes and is rarely inherited. However, certain factors may raise the chances of your child being affected.

• Family history of Angelman syndrome or related genetic disorders: If someone in your family has a known chromosomal abnormality, it could slightly increase the risk of passing on the condition.
• Parental chromosomal rearrangement: In rare cases, a parent may unknowingly carry a balanced translocation of chromosome 15. This can lead to an unbalanced version in the child, affecting the UBE3A gene.
• Having a child previously diagnosed with Angelman syndrome: If you already have one child with the condition, there may be a slightly increased likelihood in future pregnancies.
• Genetic imprinting disorders in the family: Some imprinting defects—where genes are turned on or off incorrectly—can increase risk.
• Assisted reproductive techniques: Although not a proven link, some research is exploring possible correlations with certain fertility treatments.
• Advanced maternal age is not currently identified as a direct factor, but remains under observation in broader genetic studies.

Most cases of Angelman syndrome happen randomly, without any prior family history. Still, if you're planning to have a child and are concerned, speaking to a genetic counsellor can provide reassurance and guidance tailored to your family background.

Complications

Although not life-threatening, Angelman syndrome can lead to several complications that affect your child’s quality of life. Managing these early with care and support makes a positive difference.

• Seizures: Many children develop epilepsy, typically starting between ages 2 and 3. These may require long-term anti-seizure medication.
• Feeding issues: Poor sucking or swallowing during infancy can cause undernutrition or poor weight gain.
• Sleep disturbances: Difficulty falling or staying asleep is common. This often improves with age but may still need medical or behavioural support.
• Mobility challenges: Delayed walking, poor balance, and unsteady movement may require physiotherapy and assistive devices.
• Spinal problems: A sideways curvature of the spine (scoliosis) can develop, especially in adolescence.
• Obesity risk: Reduced activity and altered metabolism in older children may increase the risk of weight gain and obesity.
• Communication difficulties: These can lead to frustration or behavioural challenges if not addressed with appropriate therapy.

How Is Angelman Syndrome Diagnosed?

Angelman syndrome is usually diagnosed in early childhood, based on observable symptoms and confirmed through genetic testing. It may also be suspected during pregnancy in certain cases.

• Delayed developmental milestones such as late crawling, walking, or first words are often the first signs parents notice.
• Unusual behaviours like frequent laughter, hand-flapping, or unsteady walking may raise concern.
• Microcephaly (a small head size) becomes noticeable by around 2 years of age.
• Seizures often begin around 2–3 years and prompt further investigation.
• Genetic testing confirms the diagnosis by identifying changes in the UBE3A gene.
• DNA methylation analysis can detect whether the maternal copy of the gene is inactive or missing.
• Chromosomal microarray or FISH tests help identify deletions or duplications that may have caused the condition.
• Exclusion of similar conditions like autism spectrum disorder or cerebral palsy is important for accurate diagnosis.

If you're worried about your child’s development, don’t delay discussing it with your doctor. Early diagnosis means early intervention and support, which can greatly benefit your child.

What Tests Are Used To Diagnose Angelman Syndrome?

Diagnosis is confirmed through a range of specialized tests:

• Genetic testing looks for deletions or mutations in the UBE3A gene.
• DNA methylation testing helps determine which parent’s gene is active.
• Chromosomal microarray analysis identifies any structural changes.
• Fluorescence in situ hybridisation (FISH) may detect missing genetic material.

Diagnosis Of Angelman Syndrome Before Birth

While rare, prenatal diagnosis is possible.

• Non-invasive prenatal screening (NIPS) tests foetal DNA in the mother’s blood.
• Amniocentesis or chorionic villus sampling (CVS) may be offered if a known family mutation exists.
• These tests carry a small risk, so they’re usually offered in high-risk pregnancies.

Diagnosis Of Angelman Syndrome After Birth

Most diagnoses occur in early childhood.

• Observing symptoms like lack of speech or poor motor coordination.
• Developmental assessments guide early suspicion.
• Genetic testing confirms the diagnosis, ruling out similar conditions like autism or cerebral palsy.

How is Angelman Syndrome Treated?

There’s no cure for Angelman syndrome, but a wide range of treatments can help manage the symptoms and improve your child’s quality of life. Angelman Syndrome treatment should always be tailored to the individual.

• Anti-seizure medications are often prescribed to manage epilepsy and should be adjusted over time as needed.
• Speech and communication therapy plays a vital role, using methods like sign language, picture boards, or speech-generating devices.
• Physical therapy improves balance, strength, and coordination, helping your child become more mobile.
• Occupational therapy supports the development of everyday skills, such as dressing, feeding, or using the toilet.
• Behavioural therapy can help manage attention span, hyperactivity, or frustration due to limited communication.
• Sleep strategies include creating consistent routines, reducing screen time, and, when needed, using melatonin or prescribed medications.
• Nutritional support may involve special feeding techniques or high-calorie diets in cases of poor weight gain.
• Education plans developed with teachers and therapists ensure that your child receives the support they need at school.
• Braces or mobility aids may be needed to support walking and posture.
• Family support groups and counselling can be incredibly helpful for coping emotionally and sharing experiences.

While Angelman Syndrome treatment won’t eliminate all symptoms, it empowers your child to live a fulfilling and happy life with support from you and their care team.

Prevention

Sadly, Angelman syndrome cannot be prevented due to its genetic nature. However, there are steps you can take if you're planning for future pregnancies.

• Genetic counselling is vital if you have a child with the condition or a known family mutation.
• Prenatal testing options may be offered if risks are identified.
• Awareness and early detection can help prepare for specialised care.
• Support networks and community resources can ease the journey for families managing Angelman syndrome.

Conclusion

Early diagnosis and personalised care make a big difference in managing Angelman syndrome. While there's no cure, ongoing support, therapies, and monitoring can help your child thrive. 

For reliable genetic testing and child-focused diagnostics, trust Metropolis Healthcare. With expert pathologists and advanced technology, they offer accurate results and compassionate care—helping you take confident steps forward in your child's health journey.

FAQs

How can I take care of my child with Angelman syndrome?

Follow treatment plans, attend therapies, monitor development, and offer emotional support through consistent care and positive reinforcement.

What questions should I ask my child’s healthcare provider?

Ask about symptoms, treatment options, therapies, genetic testing, long-term outlook, and how to support daily developmental needs.

Can Angelman syndrome be prevented?

No, it cannot be prevented as it usually results from random genetic changes during early fetal development.

What is the life expectancy of someone with Angelman syndrome?

Individuals with Angelman syndrome are typically have a near-normal life expectancy, especially with early intervention and ongoing medical support.

Is Angelman syndrome from the mother or father?

It usually results from missing or faulty genes inherited from the mother’s side, specifically the maternal UBE3A gene.

Do Angelman syndrome babies cry?

Yes, they can cry, though some may have different emotional expressions or show unusual patterns of crying.

What is the angel smile disease?

Angelman syndrome is sometimes called “angel smile disease” due to frequent smiling and joyful expressions in affected children.