Angelman Syndrome: (15q11q13) FISH Analysis

Turnaround Time

28 days; 7 day rush for infants

CPT Code(s)

88275, 88273, 88271, 88291

Cost

$584

Chromosomes

• Angelman syndrome

Angelman syndrome is characterized by severe motor and intellectual disability, absence of speech, ataxia and a characteristic open-mouthed face. Other features such as hypotonia, epilepsy and excessive laughter help in the diagnosis of the condition. Mutations in the ubiquitin-protein ligase E3A gene (UBE3A) located on chromosome 15 are known to be associated with a subset of Angelman syndrome cases.

Fluorescence in situ hybridization is a molecular cytogenetic technique in which fluorescently labeled DNA probes are hybridized to metaphase spreads or interphase nuclei. Applications include identification of structurally abnormal chromosomes, including identification of marker chromosomes, detection of very small deletions (microdeletions), and rapid detection of Down syndrome and other numerical chromosome abnormalities; and the rapid detection of sex chromosomes and the SRY gene. FISH should be used in conjunction with G-banded chromosome analysis. FISH is performed upon request when a specific numerical or structural abnormality or microdeletion is suspected. FISH is also utilized to confirm microdeletions identified during high resolution chromosome analysis and to aid in identification of abnormal chromosomes.

Blood is the accepted specimen type for this test. 5-7 ml of whole blood in a green top (sodium heparin) tube is needed for this test. For newborns and small infants, 2-3 ml of blood in a sodium heparin, green top tube is acceptable. Prenatal testing will be considered on a case-by-case basis. Please contact the laboratory prior to sending a prenatal specimen to discuss your case with a lab genetic counselor.

Specimen should be kept at room temperature; do not freeze or refrigerate. Specimen should be sent by courier or overnight mail to arrive at the laboratory the next day.

Considered on a case-by-case basis. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for most prenatal testing. Contact the laboratory prior to sending a prenatal specimen.