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The Kleberg Cytogenetics Laboratory offers a fluorescence in situ hybridization (FISH)-based assay for identifying the deletions on Xp22.3p associated with MLS/MIDAS (microphthalmia, dermal aplasia and sclerocornea) syndrome. Clinical Features:MLS is an X-linked dominant disorder characterized primarily by linear skin defects on the face and neck and eye abnormalities (microphthalmia/sclerocornea). The phenotype is variable, with some affected individuals having brain abnormalities, some degree of mental retardation and cardiac defects. The majority of patients with MLS/MIDAS are female, although there are rare reports of phenotypic males with this condition. Affected males have either a supernumerary X chromosome or a translocation involving Xp. Reasons for Referral:Patients with clinical features suggestive of MLS/MIDAS may be tested for a deletion of Xp22.3 by FISH simultaneously with high-resolution chromosomal analysis (if not previously performed). Phenotypic males may also be tested with a probe for SRY simultaneously with the MLS probe. 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 MLS/MIDAS is performed on metaphase chromosomes. The presence of one hybridization signal indicates a deletion. 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, 88273, 88271, 88291 References:1. Prakash, et al. Hum. Mol. Genet. 11: 3237-3248. Forms: >> Cytogenetics
Requisition Test Code:8470 |