Angelman Syndrome
(AS) is a neuro-genetic disorder characterized by intellectual and developmental delay, sleep disturbance, seizures, jerky movements especially hand-flapping, frequent laughter or smiling, and usually a happy demeanour. AS is a classic example of genetic imprinting in that it is usually caused by deletion or inactivation of genes on the maternally inherited chromosome 15. The sister syndrome, Prader-Willi syndrome, is caused by a similar loss of paternally-inherited genes. AS is named after a British pediatrician, Dr. Harry Angelman, who first described the syndrome in 1965. An older, alternative term for AS, happy puppet syndrome, is generally considered pejorative and stigmatizing so it is no longer used, though it remains useful as a diagnostic heuristic. People with AS are sometimes known as "angels", both because of the syndrome's name and because of their youthful, happy appearance.
Clinical features in Angelman Syndrome
The following list features of Angelman Syndrome and their relative frequency in affected individuals.
Consistent (100%)
Frequent (more than 80%)
Associated (20 - 80%)
There is currently no cure available. The epilepsy can be controlled by the use of one or more types of anticonvulsant medications. However, there are difficulties in ascertaining the levels and types of anticonvulsant medications needed to establish control, because AS is usually associated with having multiple varieties of seizures, rather than just the one as is normal cases of epilepsy. Many families use melatonin to promote sleep in a condition which often affects sleep patterns. Many individuals with Angelman Syndrome sleep for a maximum of 5 hours at any one time. Mild laxatives are also used frequently to encourage regular bowel movements and early intervention with physiotherapy is important to encourage joint mobility and prevent stiffening of the joints. Occupational therapy, speech therapy, hydrotherapy and music therapy are also used in the management of this condition.
Living with Angelman Syndrome
Although a diagnosis of Angelman syndrome is life-changing, it does not need to be life-destroying. Those with the syndrome are generally happy and contented people, who like human contact and play. People with AS exhibit a profound desire for personal interaction with others. Communication can be difficult at first, but as a child with AS develops, there is a definite character and ability to make themselves understood. It is widely accepted that their understanding of communication directed to them is much larger than their ability to return conversation. Most afflicted people will not develop more than 5-10 words, if any at all.
Seizures are a consequence, but so is excessive laughter, which is a major hindrance to early diagnosis.
The severity of the symptoms associated with Angelman Syndrome varies significantly across the population of those affected. Some speech and a greater degree of self-care are possible among the least profoundly affected. Unfortunately, walking and the use of simple sign language may be beyond the reach of the more profoundly affected. Early and continued participation in physical, occupational (related to the development of fine-motor control skills), and communication (speech) therapies are believed to improve significantly the prognosis (in the areas of cognition and communication) of individuals affected by AS. Further, the specific genetic mechanism underlying the condition is thought to correlate to the general prognosis of the affected person. On one end of the spectrum, a mutation to the UBE3A gene is thought to correlate to the least affected, whereas larger deletions on chromosome 15 are thought to correspond to the most affected.
The clinical features of Angelman syndrome alter with age. As adulthood approaches, hyperactivity and poor sleep patterns improve. The seizures decrease in frequency and often cease altogether and the EEG abnormalities are less obvious. Medication is typically advisable to those with seizure disorders. Often overlooked is the contribution of the poor sleep patterns to the frequency and/or severity of the seizures. Medication may be worthwhile in order to help deal with this issue and improve the prognosis with respect to seizures and sleep. Also noteworthy are the reports that the frequency and severity of seizures temporarily escalate in pubescent Angelman Syndrome girls but do not seem to affect long-term health.
The facial features remain recognizable but many adults with AS look remarkably youthful for their age.
Puberty and menstruation begin at around the average age. Sexual development is thought to be unaffected, as evidenced by a single reported case of a woman with Angelman syndrome conceiving a female child who also had Angelman syndrome.
The majority of those with AS achieve continence by day and some by night.
Dressing skills are variable and usually limited to items of clothing without buttons or zippers. Most adults are able to eat with a knife or spoon and fork and can learn to perform simple household tasks. General health is fairly good and life-span near average. Particular problems which have arisen in adults are a tendency to obesity (more in females), and worsening of scoliosis if it is present. The affectionate nature which is also a positive aspect in the younger children may also persist into adult life where it can pose a problem socially, but this problem is not insurmountable.