Below are some pointers about how the rare genetic disease affects adults and the therapies researchers are working on to treat patients throughout adulthood.
Symptoms of Angelman syndrome in adults
While people with Angelman syndrome will have intellectual disabilities and limited speech throughout their lives, adult patients usually have good health and are often able to steadily improve their communication and acquire new skills. Around 13% of adults with Angelman can speak at least five words. Most communicate through gesturing or with the use of augmentative and alternative communication. Around 68% of adults with Angelman are able to communicate their basic needs.
Sleep disturbances and epilepsy, which affect about 80% of Angelman children, usually improve over the years. In adults, seizures occur in about 41% of cases, although 72% of those with the disease still report poor sleep.
Constipation is another common symptom of Angelman syndrome and about 85% of adults experience it. In addition, some 32% of adults with Angelman tend to be overweight due to factors such as genetic composition, an abnormal sense of satiety, and mobility problems.
Scoliosis, or the abnormal sideways curvature of the spine, is frequent in Angelman.
Researchers have reported the condition in about 20% of children and 50% of adults with the disease. Some 68% of adults are able to walk independently. However, some mobility may be lost as patients age, and joints may stiffen.
A study published in the American Journal of Medical Genetics showed that 47% of adolescents and 71% of adults with Angelman had anxiety issues. According to Angelman UK, 52% of adults exhibit self-injurious behaviour.
Potential new treatments
Right now, available treatments focus on managing the disease’s symptoms. If it wins U.S. Food and Drug Administration approval, OV101 (gaboxadol) would be the first medicine in the U.S. that treats Angelman’s underlying cause. Researchers are currently testing the oral small molecule, which is being developed by Ovid Therapeutics, in adolescents and adults with the disease.
The results from a recently completed Phase 2 study, known as the STARS trial (NCT02996305), showed that the experimental treatment — one of several that scientists are developing — improved the Clinical Global Impression score as well as sleep, behaviour, and motor function in adults and adolescents. The treatment also was found to reduce anxiety.
The randomized, double-blind, placebo-controlled trial enrolled 78 participants, ages 13 to 49, with a confirmed diagnosis of Angelman syndrome. In trials, the experimental therapy has proven generally safe; most side effects are mild.