Angelman syndrome occurs in approximately one in 15,000 live births. This rare disorder is classified as both a neurological and a genetic disorder. This complex condition mostly affects the patient’s nervous system and causes an array of symptoms. Between six to 12 months old, the developmental delays usually start to become noticeable. Those with this condition often laugh and smile frequently and have excitable and happy personalities.
On chromosome 15, there is a specific gene that when defective leads to Angelman syndrome. The gene is called the UBE3A gene, or ubiquitin protein ligase E3A. People get pairs of genes from both of their parents. This includes a paternal one from the father and a maternal one from the mother. Under normal circumstances, the cells use information from both maternal and paternal copies. However, for a few genes, there is only a single active copy.
In the brain, the UBE3A maternal copy of this gene is active. In most people with this syndrome, the maternal copy of this gene is either damaged or missing. However, there are a few cases where instead of getting a copy of this gene from each parent, the person inherits two paternal copies of it, resulting in Angelman syndrome.
Researchers do not yet know why the genetic changes happen that cause this condition. In most cases, those with this syndrome do not have a family history of it. However, if someone does have a family history of this disorder, researchers believe that any children that they have are at an increased risk of developing it.
1. Speech Delay
Significant communication difficulties and developmental delays are possible with this condition. In terms of speech delay, some children may not speak at all, while others will say limited words. In most cases, patients will only be able to say a few words. Children may have difficulty both expressing their thoughts and understanding what is being communicated to them. They might only be able to communicate by using facial expressions. While expressive language is typically impaired among those with this disorder, their receptive language might be more advanced. The issues with speech and communication might play into the child experiencing learning difficulties.
When patients with Angelman syndrome are experiencing speech difficulties, there are possible interventions that could potentially aid them in communicating more clearly. It is generally recommended that parents take advantage of early intervention and get started with these methods as soon as possible with their child. Due to the significant limitations in verbal speech, interventions generally focus on alternative and augmentative communication. Children utilizing this type of therapy may learn to communicate more effectively using aided communication, such as voice output communication aids or picture communication symbols. They might also learn unaided communication forms, such as gestures, eye gaze, manual signs and finger spelling.
2. Abnormality Walking
When this disorder is mild, children may start to walk when they are between two and three years of age. However, they might not begin walking until they are between five and 10 years of age in severe cases. In approximately 10 percent of patients, they are not able to walk without assistance. Ataxia is common among those with this condition, resulting in the patients not being able to properly coordinate their voluntary movement. When the patients are walking, their movement may appear noticeably stiff, slow and jerky. Diminished muscle tone and exaggerated reflexes are also possible with this condition. Issues with movement can sometimes be noticeable as early as six to 12 months old.
3. Speech Impairment
Severe speech impairment is not uncommon in children with this disorder. Patients may not speak at all, or they might speak a little. Attention deficit may also impact the speech abilities of the child. Tongue thrusting can occur with this syndrome and this might negatively impact the patient’s ability to speak. Some patients laugh at times that are generally considered to be inappropriate. Their nonverbal communication may also be abnormal. Children with this disorder might repeatedly flap their hands when they are excited about something. When they are doing this, they usually hold their arms up and have their elbows and wrists bent.
4. Lazy Eye
Eye issues are not uncommon among those with this syndrome. Amblyopia, or a lazy eye, refers to vision being reduced in one eye due to abnormal visual development during early childhood. The eye that is considered “lazy” generally wanders either outward or inward. While rare, it can sometimes affect both eyes. When someone has a lazy eye, the eyes look like they are not working together. It can cause abnormal results when the patient goes through vision screening tests, poor depth perception, head tilting an either shutting or squinting an eye to attempt to see more clearly. In addition to lazy eye, those with Angelman syndrome might experience the following visual issues: poor visual tracking, hyperopia, aniridia and nystagmus.
5. Seizures
In most cases, seizures start to occur when the patient between two and three years old. Approximately seven to eight out of 10 patients with this disorder will experience seizures. They usually occur without a fever being present. There are different seizure types patients may experience, including myoclonic jerks, tonic stiffening and astatic drops. While less common, it is also possible for focal and tonic-clonic seizures to occur. A seizure type referred to as non-convulsive status epilepticus is possible. With this type, the patient is usually unresponsive, very quiet, unable to eat and drooling excessively. This state can last for minutes, or in some cases, it spans several days. It may happen repeatedly for days or weeks.
6. Drooling
The majority of children with this syndrome drool, but the degree of severity varies greatly. In some cases, this symptom improves with age, but this is not always the case. The drooling appears to be worse for some patients when they are warm or spending time outside. In severe cases, surgery is a possible treatment for doctors and patients to explore, but some dentists recommend against it since the excess saliva can actually reduce the risk of cavities since it cleans the teeth. Occupational therapy might be helpful if the child experiences drooling along with swallowing difficulties associated with the tongue’s position in the mouth.
7. Sleep Disorder
Those with this disorder tend to have abnormal sleep-wake patterns. The result of this abnormality is that they do not have to sleep as much as most people. For example, a person with this syndrome may only need to sleep five hours a night to feel rested where the average person needs approximately seven to nine hours per night. As the patient gets older, the sleep issues might start to improve on their own without intervention. When the sleep issues are present, behavioral therapy and medications may be helpful to ensure that patients are able to get restful and sufficient sleep each night.
