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Matt Amey Biology 1 Honors 1st block Ms. Beatty Angelman Syndrome

Introduction:
Angelman Syndrome is a genetic characterized by intellectual and developmental delay, sleep disturbance, seizures, jerky movements, frequent laughter or smiling, and usually a happy demeanor. AS is an example of genetic imprinting in that it is usually caused by deletion or inactivation of genes on the maternally inherited chromosome 15. AS is named after a British pediatrician, Dr. Harry Angelman, who first described the syndrome in 1965. An older, alternative term for AS, happy puppet syndrome, is generally considered offensive so it is no longer used, though it remains useful as a diagnostic heuristic. People with AS are sometimes known as "angels", both because of the syndrome's name and because of their youthful, happy appearance.

(Karyotype for Angelman Syndrome)

Mode of Inheritance:
In patients with Angelman Syndrome, a small part of chromosome 15 are found to be missing or deleted. The gene that is responsible for Angelman Syndrome, UBE3A, only causes the syndrome when it is turned off or missing. In Angelman Syndrome, the gene is only missing in the chromosomes that were passed on from the mother. Researchers have found that Angelman Syndrome occurs when both chromosome 15s are inherited from the father. This condition is called uniparental disomy. In the case of Angelman Syndrome, both chromosomes inherited have the UBE3A gene turned off on them. Angelman Syndrome may also be caused by mutations in the Imprinting Center that can cause the UBE3A gene to turn on or off.

(Child with Angelman Syndrome)

Clinical Description of the Disorder:
People with Angelman Syndrome often suffer from stiff, unstable jerky movement, absent or diminished speech skills, hand flapping, excessive laughter/unusually happy demeanor, developmental delay, and small head size. Often, patients also develop epilepsy and have trouble with balance.

Treatment:
There are no specific treatments for patients with Angelman Syndrome. Medication and medical therapy is common to prevent and lessen seizures from epilepsy. Physical and occupational therapies, behavioral therapies, and communication therapy are important in allowing patients to reach their full development.

Detection:
Without genetic tests, it's often difficult to detect whether a child has Angelman Syndrome or not. Signs of Angelman Syndrome usually don't appear until the child reaches age 1 and they are missing certain milestones. Phenotypes of children with AS are usually microcephaly (small head), flat back of head, wide mouths, spaced teeth, and prominent mandibles.

Sources:

 * "Angelman Syndrome Causes, Symptoms, Diagnosis, and Treatment Information on MedicineNet.com." Web. 25 Apr. 2010. .


 * "What Is AS - Testing 101." //Foundation for Angelman Syndrome Therapeutics//. Web. 25 Apr. 2010. .


 * "Angelman Syndrome - Genetics Home Reference." //Genetics Home Reference - Your Guide to Understanding Genetic Conditions//. Web. 25 Apr. 2010. .