Diseases & Conditions
A childhood disorder characterized by HYPERACTIVITY, seizures, laughter, and developmental delays. Initially presumed to be rare, it is now believed that thousands of children with Angelman syndrome (AS) have gone undiagnosed, or been misdiagnosed with CEREBRAL PALSY, AUTISM, or other childhood disorders.
In 1965 English physician Harry Angelman, M.D., ﬁrst described three children with characteristics now known as Angelman syndrome, including stiff, jerky gait; lack of speech; excessive laughter; and seizures. Other cases were eventually published, but the condition was considered to be extremely rare and many physicians doubted its existence. The ﬁrst reports from North America appeared in the early 1980s, and since then many new reports have appeared.
In the United States and Canada today, there are about 1,000 diagnosed individuals, but the condition has been reported throughout the world among divergent racial groups. In North America, however, most cases seem to occur in Caucasian children.
Angelman syndrome is usually not recognized at birth or in infancy, since the developmental problems are hard to spot at that time. Parents may ﬁrst suspect the diagnosis after reading about AS or meeting a child with the condition. The most common age of diagnosis is between age three and seven, when the characteristic behaviors and features become evident.
Hyperactivity and a short attention span are probably the most typical behaviors, which affect boys and girls about equally. Infants and toddlers may be continually active, constantly keeping their hands or toys in their mouth, moving from object to object. In extreme cases, the constant movement can cause accidental bruises. Older children may grab, pinch, and bite. A child’s attention span can be so short that it interferes with social interaction, since the child cannot pay attention to facial and other social cues.
Laughter is also quite common, which seems to be a reaction to physical or mental stimuli. Although AS children experience a variety of emotions, continual happiness is most common. Parents may ﬁrst notice this laughter at the age of one to three months. Giggling, chortling, and constant smiling soon develop and appear to represent normal reﬂexive laughter, but cooing and babbling are delayed.
Other symptoms include
• developmental delay
• severe speech impairment with almost no use of words
• movement or balance disorder
• easily excitable personality, often with handﬂapping movements
• abnormally small head
Persistent and consistent behavior modiﬁcation helps decrease or eliminate unwanted behavior. In milder cases, attention may be sufﬁcient enough to learn sign language and other communication techniques. For these children, educational and developmental training programs are much easier to structure and are generally more effective. Most children do not receive drug therapy for hyperactivity although some may beneﬁt from use of medications such as methylphenidate (RITALIN).