Health Conditions A-Z Rare Diseases What Is Angelman Syndrome? Angelman syndrome is a complex genetic disorder that primarily impacts the nervous system. By Korin Miller Updated on January 24, 2023 Medically reviewed by Brigid Dwyer, MD Medically reviewed by Brigid Dwyer, MD Brigid Dwyer, MD, is a board-certified neurologist and an assistant professor of Neurology at Boston University. learn more Share Tweet Pin Email Angelman syndrome is a complex genetic order that primarily impacts the nervous system. It can lead to developmental delays, intellectual disability, severe speech impairment, and problems with movement and balance. Many children with Angelman syndrome have epilepsy, i.e., seizures, Ira Goldstein, MD, director of the Center for Neurotrauma at Rutgers New Jersey Medical School, told Health. They may also have a smaller head size. In 2007, actor Colin Farrell shared his son has Angelman syndrome. Their family went on to spread awareness and provide supportive messages to other families. In 2020, Farrell told People, "Everything [my son has] achieved in his life has come through the presence and the kind of will that is hard work." Learn more about Angelman syndrome symptoms, causes, treatments, and long-term outlook below. Angelman Syndrome Symptoms People with Angelman syndrome usually start to develop noticeable symptoms by six to 12 months, Dr. Goldstein said. Other signs of the condition show up in early childhood. Those can include: Small head sizeDevelopmental delaysFacial features that are rounded and heavy with thickened skinA happy, excitable demeanorHyperactivityA short attention spanFascination with waterDifficulty sleepingIntellectual disabilitySevere speech impairmentSeizuresScoliosis Individuals with Angelman syndrome may have distinctive facial features, including a prominent chin, deep-set eyes, an abnormally wide mouth with a protruding tongue, widely-spaced teeth, and an unusually flat back of the head. What Causes Angelman Syndrome? Angelman syndrome is a condition people are born with. "There are no known risk factors for Angelman syndrome," Melissa Santos, Ph.D., a pediatric psychologist at Connecticut Children's Medical Center, told Health. The condition is genetic, Dr. Santos said, "so there is some thought that if you have someone in your family with it, you have a higher risk." Overall, though, the condition is rare, affecting one in 12,000 to 20,000 people. In Angelman syndrome, a copy of the mother's specific gene—the UBE3A gene— is missing or damaged. If the missing gene is from the father, the diagnosis will be Prader-Willi syndrome. This is one of the very few diseases where "imprinting" (essentially, the gender of the parent who passed the gene on) is essential to the diagnosis and prognosis. Unlike other genes, the UBE3A gene is subject to imprinting with expression only from the mother's chromosome. Treatments for Angelman Syndrome Symptoms "Treatment involves treating the symptoms," Dr. Goldstein said. That may mean taking medication to try to lower the risk of seizures or even having surgery in an attempt to prevent seizures if medications don't work, Dr. Goldstein said. "If they are experiencing behavioral concerns, they may see a psychologist or other mental health provider to [help] focus on ways to improve that," Dr. Santos said. If a child with Angelman syndrome is nonverbal or has limited language abilities, they may see a speech therapist to learn how to communicate—either through sign language, an iPad, or other options. People with Angelman syndrome may also undergo physical therapy to build strength and coordination if they have mobility issues. "They may have all or some of these treatments, and it really varies on the person," Dr. Santos added. Long-term Outlook Daniel Ganjian MD, a pediatrician at Providence Saint John's Health Center in Santa Monica, California, told Health it's "extremely unlikely" someone with Angelman syndrome will be able to live on their own. "They are poorly able to communicate to people who don't know them well, and they often have significant impairment," Dr. Goldstein said. "Sometimes these problems can't be addressed easily by someone who doesn't know them.' "Most adults with Angelman can speak up to five words, and less than 70% can communicate using other resources," Dr. Santos said. "It is the developmental delays and language that may lead to them needing a conservatorship in order to help support them." In some cases, adults with Angelman syndrome may move into a group care setting, Dr. Goldstein said. The Most Common Types of Learning Disabilities Found in Kids and Adults, According to Experts A Quick Review Angelman syndrome is a rare genetic disorder that can affect a person's nervous system, physical features, and communication ability. While no cure exists, therapies and treatments exist to help manage symptoms, gain physical strength, and potentially improve communication skills. Talk to a healthcare provider to find support for managing Angelman syndrome. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit Sources Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. MedlinePlus. Angelman syndrome. People magazine. Colin Farrell: My Son 'Is an Absolute Stud.' National Organization for Rare Disorders (NORD). Angelman Syndrome. Angelman Syndrome Foundation. Genetics of AS. Angelman Syndrome Foundation. The role of antisense RNA Ube3a-ATS in Ube3a imprinting and Angelman syndrome.