Angelman and Prader-Willi Syndromes, DNA Analysis

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.