Angelman Syndrome

From WikiGenetics

1 Name of Condition
2 Definition
3 Description, Signs and Symptoms
4 Inheritance
5 Demographics
6 Diagnosis
7 Treatment and Management
8 Prognosis
9 Resources
10 References

[edit] Name of Condition

Angelman Syndrome

[edit] Definition

Angelman Syndrome is a genetic condition that affects the nervous system, resulting in mental deficiencies, distinct physical characteristics, and an unusually excitable demeanor.

[edit] Description, Signs and Symptoms

Angelman Syndrome is usually noticable between the ages of 6 months and 1 year, when parents or a physician notice that the child is not developing at the expected pace. Diagnosis may not occur until several years later. Symptoms include:

developmental delay and/or mental retardation
severe speech impairment
seizures
small head size
movement and balance problems
happy demeanor, lots of laughing and smiling
sleep disturbance

[edit] Inheritance

Angelman Syndrome is caused by changes in the UBE3A gene on the 15th chromosome, and the OCA2 gene is also related. Normally, the child inherits two copies of the 15th chromosome, one from each parent. The body deactivates the UBE3A gene that is on the parental chromosome, so that only the gene from the mother's chromosome is active. However, if this portion of the mother's chromosome is defective or missing, the child will be born with Angelman Syndrome. About 70% of cases result from deletion of the gene, and in about 11% of cases it is due to a mutation. In other cases the root genetic cause is unknown.

[edit] Demographics

Although the actual prevalence of Angelman Syndrome is unknown, it is the most common childhood neurological condition, and seems to be present at equal frequencies in many different races. Estimates of prevalence are between 1 in 12,000 to 1 in 30,000 people worldwide.

[edit] Diagnosis

Diagnosis of Angelman Syndrome can be frustrating because some of the symptoms are not terribly unique. Although it is evident at a young age that a child has developmental issues and other physical and mental problems, it is difficult to diagnose this condition correctly because of it's rarity. Sometimes it may take years after an initial consultation to confirm the diagnosis. A genetic test can be done to confirm the diagnosis, by analyzing the methylation of the DNA.

[edit] Treatment and Management

Treatment of Angelman Syndrome is normally on a symptomatic basis. Medications may be used to control seizures or hyperactivity. Behavioral, physical, and occupational therapy may greatly benefit some children to adapt them to school and daily life.

[edit] Prognosis

Individuals with Angelman Syndrome do face intellectual and developmental difficulties, however, with proper treatment and therapy there is no significant shortening of the lifespan. Early diagnosis is very beneficial to maintaining quality of life.