Angelman syndrome

Individuals with Angelman syndrome are most likely to have the following health concerns:

• Feeding problems - feeding difficulties are most common in infants, due to poor sucking and swallowing abilities
• Ataxia - difficulty with movement coordination, which causes an unsteady walk and jerky movements
• Seizures - there are variety of seizure types that have been reported in people with Angelman syndrome, and most individuals require medication to prevent seizures as much as possible
• Sleep difficulty - most commonly, night-time wakefulness, difficulty with sleep-awake cycles, difficulty falling or staying asleep, decreased need for sleep
• Strabismus - crossing of one or both eyes; sometimes corrected with surgery
• Excessive mouthing/chewing behaviors, abnormal food-related behaviors
• Scoliosis
• Obesity (later in life)

There are a number of disorders whose symptoms overlap with those seen in Angelman syndrome, including:

• Adenylosuccinate lyase deficiency
• Christianson syndrome
• Kleefstra syndrome
• MECP2-related disorders
• Microdeletion of chromosome 2q23.1 involving the MBD5 gene
• Mowat-Wilson syndrome
• Phelan-McDermid syndrome
• Pitt-Hopkins syndrome

Individuals with Angelman syndrome have a happy demeanor and often laugh or smile for no apparent reason. This happy disposition along with jerky movements, developmental disabilities, and little or no speech are characteristic of the disorder.

While the typical features of Angelman syndrome include developmental delays, intellectual disabilities, severe speech impairment, ataxia (a movement disorder), seizures, microcephaly (small head), sleep disturbances, and hyperactivity, there are also a number of symptoms that are not seen in every person with Angelman syndrome. There are also some generalizations about the severity of certain features that can be made based on the type of genetic change the person has. (For information about the genetics of Angelman syndrome, please see the "Causes" section.)

• Individuals who have Angelman syndrome as the result of a deletion of their maternally-inherited copy of UBE3A typically have the most severe symptoms in terms of ataxia, poor muscle tone, feeding problems as babies, seizures, speech impairment, and small head size (microcephaly). If the deletion also includes a nearby gene called OCA2, it causes very fair pigmentation (light eyes, skin and hair).
• Individuals who have Angelman syndrome as the result of inheriting two copies of their father's chromosome 15 / the region around and including the UBE3A gene may have better growth, including a more typical head size, as well as fewer problems with movement coordination and seizures.
• Individuals who have Angelman syndrome as the result of a genetic change in the imprinting center or who have uniparental disomy (two copies of UBE3A from their father) typically have less severe intellectual disabilities and speech impairment compared to other causes of Angelman syndrome.

It is important to keep in mind that not every person with Angelman syndrome will have the exact same symptoms.