The main characteristics of Angelman syndrome are severe intellectual disability, ataxia, lack of speech, and excessively happy demeanor.
Angelman syndrome results from a loss of gene activity in a specific part of chromosome 15, the 15q11-q13 region.
This region contains a gene called UBE3A that, when mutated or absent, likely causes the characteristic features of this condition.
Deletion of same chromosome region as Prader-Willi syndrome except the chromosome deletion region is derived from the mother: chromosome 15 mutation.
People normally have two copies of the UBE3A gene, one from each parent.
Both copies of this gene are active in many of the body’s tissues. In the brain, however, only the copy inherited from a person’s mother is active.
If the maternal copy is lost because of a chromosomal change or a gene mutation, a person will have no working copies of the UBE3A gene in the brain.
Mentally retarded, ataxia and associated with inappropriate laughter.
A genetic condition that only affects about 1 in 16,000 people.
They suffer from developmental disabilities as well as other problems.
A neurological condition that primarily affects the nervous system.
Has a specific gene known as the UBE3A gene.
In the majority of Angelman syndrome cases, the maternal copy of this gene is missing entirely.
In some others, that maternal UBE3A gene is mutated rather than missing.
There are some instances in which the gene abnormality comes from the father’s copy of the gene, but these are much rarer.
Symptoms and signs of Angelman syndrome generally do not show up until between 6 and 12 months of age.
Symptoms include a lack of babbling or other vocalizations and an inability to begin crawling or scooting on their own.
An inability to walk can also be an early sign of this syndrome.
Symptoms and findings include: language impairment, bouts of frequent laughter, seizures, restlessness, microcephaly, excitability, and trouble sleeping or not needing a normal amount of sleep.
The causes of Angelman syndrome are genetic, the indicator is a genetic mutation on chromosome 15.
When only one part of the gene is activated in the brain, then the child will display the symptoms of Angelman syndrome.
In about 11% of cases, Angelman syndrome is caused by a mutation in the maternal copy of the UBE3A gene.
In a smaller percentage, it is caused when the patient inherits two copies of chromosome 15 from their father instead of one copy from each parent.
About 70% of cases occur when parts of the chromosome 15 are deleted.
Rarely, it’s caused by gene translocation or mutation.
If the mother’s UBE3A is missing or not activated in the brain, difficulties in different aspects of the nervous system.
No cure exists.
Occupational and physical therapy help with mobility and problems with daily living tasks.
Behavioral therapy, communication therapy, and speech pathology are helpful.
Some patients benefit from back braces or spinal surgery to correct curvatures in the spine that occur.
Anticonvulsants, are used in some patients with seizures that sometimes occur, beginning around the age of 2.