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| The Kleberg Cytogenetics Laboratory offers a fluorescence in situ hybridization (FISH)-based assay for identifying the duplication on 11p15.5 associated Beckwith-Wiedemann syndrome. Clinical Features:Beckwith-Wiedemann is an overgrowth syndrome characterized by macrosomia, macroglossia (large tongue), omphalocele, neonatal hypoglycemia and ear creases. Individuals with Beckwith-Wiedemann syndrome are at increased risk for certain tumors such as Wilms tumor and neuroblastoma. Reasons for Referral:Patients with clinical features suggestive of Beckwith-Wiedemann syndrome may be tested for a duplication of 11p15.5 by FISH simultaneously with high-resolution chromosomal analysis (if not previously performed). Prenatal diagnosis may be performed if an affected family member has been studied in our laboratory and has been shown to have a duplication detectable by FISH. Please call regarding all prenatal samples. Testing Methodology:FISH is the application of fluorescently labeled DNA molecules to metaphase chromosomes and interphase nuclei for the detection of chromosome abnormalities and alterations. It is a rapid, reliable and direct approach for identifying patients with microdeletions or microduplications. FISH analysis for Beckwith-Wiedemann syndrome is performed on interphase chromosomes. The presence of three hybridization signals indicates a duplication. Only a small number of patients (1-2%) with Beckwith-Wiedemann syndrome will have a duplication detected by FISH. The majority of patients have other molecular abnormalities such as paternal uniparental disomy or other abnormalities of methylation. Specimen Requirements:Whole blood
in sodium heparin (green-top) tubes: Shipping and Handling:All tubes must be labeled with the patient's testname and date of birth, and a completed requisition form must accompany each sample. If the laboratory is billing the patient's insurance, please enclose a copy of the insurance card. Ship specimens for overnight delivery at ambient temperature. Please notify the laboratory of incoming samples. Turnaround Time:7-10 days CPT Codes and Prices:88230, 88271, 88273, 88291 References:1. Shuman, et al. (2003) Gene Reviews. Forms: >> Cytogenetics
Requisition Test Code:8460 |