The Kleberg Cytogenetics Laboratory offers a fluorescence in situ hybridization (FISH)-based assay for identifying the deletion of 5p15.2 associated with cri-du-chat syndrome. Clinical Features:Individuals with cri-du-chat syndrome have dysmorphic facial features, microcephaly, growth deficiency, mental retardation, speech delay and a characteristic “cat-like” cry. Reasons for Referral:Patients with clinical features suggestive of cri-du-chat syndrome may be tested for a deletion of 5p15.2 by FISH simultaneously with high-resolution chromosomal analysis (if not previously performed). The majority of deletions are detectable with high-resolution chromosomal analysis. Prenatal diagnosis may be performed if an affected family member has been studied in our laboratory and has been shown to have a deletion 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 deletion 5p15.2 is performed on metaphase chromosomes using a commercially available probe. The presence of one hybridization signal indicates a deletion. Virtually all individuals with cri-du-chat syndrome will have a deletion identified by either high-resolution chromosome studies or FISH. 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. Church, et al. (1997) Genomic Res. 7: 787-801. Forms: >> Cytogenetics
Requisition Test Code:8464 |