Angelman and Prader-Willi Syndromes, DNA Analysis

Casandra

Casandra Test Code LC96285Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 511210CPT Code 81331

Angelman and Prader-Willi Syndromes, DNA Analysis

Also known as: Prader-Willi and Angelman Syndromes, DNA Analysis, PWS Methylation Assay

Clinical Use

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Use

This test detects all major causes of the Prader-Willi and Angelman syndromes. Angelman syndrome (AS) (OMIM 105830) is characterized by severe developmental delay or intellectual disability, severe speech impairment, gait ataxia and/or jerking limb motions, and an inappropriate happy demeanor that includes frequent laughing, smiling, and excitability. Neonatal hypotonicity may also occur. Approximately 70% of AS patients have a deletion of 15q11-13 in the maternally contributed chromosome 15, with about 3% to 5% of AS cases resulting from paternal uniparental disomy (UPD). Approximately 11% of AS cases result from mutations in the maternal copy of the UBE3A gene that also maps to 15q11-13. An abnormality of the imprinting process occurs in a portion of the remaining patients.

Special Instructions

Please provide pertinent findings, family or personal, of intellectual disability, autistic behaviors, developmental delay, and obesity. All fetal specimens, including cord blood, must be accompanied by a maternal blood or buccal swab for maternal cell contamination (MCC). A separate requisition should be submitted with the maternal specimen.

Limitations

Approximately 11% of Angelman syndrome cases arising from UBE3A mutations will not be detected by this test. This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the FDA.

Test Details