PRENATAL ANEUPLOIDY SCREEN BY FISH
FISH testing for Anueploidy - AneuVysion® - Prenatal FISH - Fluorescence In Situ Hybridization - Cytogenetics
Classical chromosome analysis; AF-AFP testing for gestational ages 14.0-22.9 weeks; Prenatal FISH probes for X, Y, 13, 18, and 21.
This is a FISH test used to detect aneuploidy of chromosomes X, Y, 13, 18, and 21, and is offered in conjunction with routine cytogenetic analysis. It is not intended to be a stand-alone test. The American College of Medical Genetics recommends that irreversible therapeutic action should not be taken on the basis of FISH results alone.
Specimen Collection Requirements
Amniotic Fluid, obtained using sterile technique
This is not a stand-alone test, the volume must be sufficient to include classical chromosome analysis. The first 1.0-2.0 mL should be expressed into a separate tube to clear the specimen of possible maternal cells. Distribute the rest of the specimen between three screw-top sterile polystyrene or polypropylene tubes. For cytogenetics testing, all drawn amniotic fluid should be sent, properly labeled, to the Cytogenetics laboratory. Do not refrigerate, freeze, or expose to extreme temperatures. Bloody amniotic fluid samples are not appropriate for FISH testing due to the possiblity of maternal cell contamination. To insure the completion of the classical cytogenetics testing, if gross blood is present, add 0.25 mL of sodium heparin (1,000 units/mL) aseptically to each tube immediately after the tap. This should be noted on the tube. Keep specimen at ambient temperature and transport within 24 hours. Maintain sterility, do not split specimen or open tubes.
Room temperature within 24 hours of collection
Ambient: 24 hours; Refrigerated: Suboptimal, call Cytogenetics,(503) 413-4613; Frozen: Unacceptable
Clinical information including the indication for study must accompany the specimen. This includes the gestational age, ultrasound findings, prenatal screening results, previous reproductive history and any known family history of birth defects. Requisitions for cytogenetics studies are available upon request.
Fluorescent In Situ Hybridization(FISH) is performed on fetal cells obtained from amniotic fluid. An FDA approved assay called AneuVysion is used.
Legacy Laboratory Services
FISH testing will be reported as a preliminary report. The final report will also include the results and interpretation of the classical cytogenetic analysis. A computer generated karyotype is also provided with each study.
46,XX, apparently normal female
46,XY, apparently normal male
If Genetic Counseling is needed, call (503) 413-5214.
Thursday, January 5, 2017 03:42:25 AM