ANGELMAN SYNDROME

ALTERNATE NAMES

AS

DESCRIPTION

Angelman Syndrome (AS) is a rare genetic neurological disorder that involves a deletion of chromosome 15q and mutation of the UBE3A gene. It is characterized by developmental delay, intellectual disability, severe speech impairment with a limited vocabulary (usually consisting of less than 10 words), small head size (microcephaly), hypotonia (reduced muscle strength), scoliosis (curved or crooked spine), and ataxia (difficulties with coordination, balance and spasticity). Some children with this disorder experience recurrent seizures varying from major motor to a sudden brief lapse in muscle tone (akinetic). Children with AS are described as generally happy with an excitable demeanor and frequent smiling, laughter, and hand-flapping movements. Hyperactivity and a short attention span are common. Developmental delays become noticeable by age 6 to 12 months, and seizures generally begin between 2 and 3 years of age. Many children with AS also have difficulty sleeping.

DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM CODING

The diagnosis of AS is established by a combination of clinical features and molecular genetic testing and/or fluorescent in situ hybridization (FISH) analysis.

ICD-9: 759.89

ONSET AND PROGRESSION

People with AS survive into adulthood but continue to have severe cognitive and communication impairments. The seizures tend to improve with age.

TREATMENT

There is currently no cure for this disorder. Management of AS includes treatment of seizures, physical and occupational therapies to improve adaptive functioning, and speech therapy with a focus on non-verbal methods of communication. School age children require individualized and flexible instructional curricula.

Suggested MER for Evaluation:

• Clinical examination that describes diagnostic features of the impairment and laboratory findings are needed to confirm the diagnosis.

• Developmental assessment or psychological testing to address allegations of mental impairment may be warranted.

Suggested Listings for Evaluation:

DETERMINATION

 LISTING 

REMARKS

Meets Listing

12.05

110.08B

112.05

AS involves multiple body systems. A description of clinical and laboratory findings will be needed to adjudicate these cases.

Medical Equals