Diagnostic Cytogenetics Inc.’s quick and accurate analysis will provide your patient with true peace of mind. Our laboratory genetic counselor is always available for consultation and research for prenatal indications and testing.
Diagnostic Cytogenetics Inc. (DCI) can perform chromosome analysis on amniotic fluid, chorionic villus, and percutaneous umbilical blood (PUBS) specimens
Indication for Testing
• Advanced maternal age
• Confirmation of an abnormal screening result.
• Fetal abnormalities on ultrasound that are suggestive of a chromosomal defect.
• Previous offspring with a chromosomal abnormality.
• Family history of chromosomal abnormality.
Chromosome Analysis Detects:
• Aneuploidy (monosomy, trisomy)
• Deletions and duplications (>5Mb)
Chromosome Analysis Does Not Detect:
• Deletions or duplications that are too small to be seen by microscope (<5Mb)
For amniotic fluid specimens, the in-situ method of cell culture and clonal analysis is performed. G-banded metaphase spreads from 12-15 clones from a minimum of 2 independent cultures are examined. For CVS and PUBS samples, G-banded chromosomes from 20 metaphase cells are examined.
For all samples, 5 cells are completely analyzed and at least 3 karyograms are prepared. Additional chromosome analysis and special banding techniques are employed as needed.
DCI can also culture prenatal specimens to forward to an outside laboratory for testing. Please inquire for more details.
Please see our FISH page for our full test menu.
Aneuvysion FISH Panel
Aneuvysion Fluorescent In Situ Hybridization (FISH) can be performed on prenatal samples for rapid detection of the most common chromosome gains and losses seen prenatally.
Aneuvysion FISH testing is suggested for the following indications:
• Late gestation pregnancies that require a rapid result.
• Rapid confirmation of an abnormal prenatal screening result
• Detection of fetal abnormality on ultrasound that suggest aneuploidy of chromosomes X, Y, 13 18, or 21.
• Newborn with multiple anomalies that suggest aneuploidy of chromosomes X, Y, 13, 18, or 21.
Probe Target Abnormality RB1 Trisomy 13 D18Z1 Trisomy 18 D21S259 Trisomy 21 DXZ1 Sex Chromosome Aneuploidy DYZ3 Sex Chromosome Aneuploidy
Preliminary results are available on an average of 24 hours after specimen receipt in laboratory.
FISH results are considered preliminary until confirmed by classical cytogenetic analysis.
• Rapid aneuploid screening provides only numerical information about selected chromosomes. It is not designed to detect structural rearrangements, mosaicism, or other numerical abnormalities.
• The results from this technique are considered preliminary and cytogenetic analysis must also be ordered on all samples.
• Amniotic fluid samples contaminated with blood may be excluded.
• When the specimen volume is not sufficient to meet the minimum requirements for processing both FISH and standard cytogenetic procedures, chromosome analysis will take precedence.
• FISH assays may not be informative if the specimen quality and/or slide preparation is inadequate.
• Amniotic fluid samples from early gestation pregnancies may not contain enough cells for informative results in the FISH analysis.
• Amniotic fluid samples from late gestation pregnancies may contain excess debris, which could make the FISH assay uninformative.
Rapid aneuploid screening utilizes fluorescent DNA probes, which bind to specific regions of chromosomes 13, 18, 21, X, and Y in interphase (non-dividing) cells. These probes produce bright colored signals that are examined under a fluorescence microscope.
These probes are applied to amniotic fluid cells (no cell culture is necessary). Fifty interphase cells for each probe (13, 18, 21, X, and Y) are scored.
Microdeletion/Microduplication Syndrome Probes
FISH on metaphase cells can also be performed to identify the following microdeletion/microduplication syndromes:
Syndrome Name Chromosome Location Probe/Gene Locus Wolf-Hirschhorn syndrome 4p16.3 D4S96 Cri du chat syndrome 5p15.2 D5S23 Williams syndrome 7q11.23 Elastin Retinoblastoma 13q14.2 RB1 Prader-Willi/Angelman syndrome 15q11.2-q13 SNRPN/D15S10 Smith-Magenis syndrome 17p11.2 FLI1 and RAI1 Miller-Dieker syndrome 17p13.3 LIS1 22q11.2 Deletion Syndrome (DiGeorge, Velocardiofacial Syndrome) 22q11.2 TUPLE1 (D22S553, D22S609, D22S942) Steroid Sulfatase Deficiency/X-linked Ichthyosis Xp22.3 STS Kallmann Syndrome 1 Xp22.3 KAL1
Fluorescence in-situ Hybridization (FISH) utilizes DNA probes that bind to a specific region of a chromosome. These probes produce bright colored signals that are examined on a fluorescence microscope. For metaphase FISH, ten to fifty cells are scored (depending on the probe used).
Test Turnaround Time* CPT Codes** Chromosome Analysis- Amniotic Fluid 7.5 days, average 88235, 88267 or 88269, 88280×2, 88285, 88291 Chromosome Analysis- CVS 7-14 days 88235, 88267, 88280×2, 88285, 88291 Chromosome Analysis- PUBS 2-7 days 88230, 88262, 88280, 88289, 88291 Aneuvysion FISH 24 hours for preliminary, final reported with chromosome analysis 88377×2 Metaphase FISH Reported with chromosome analysis 88377
*All turnaround times are business days from specimen receipt to report issued. Averages include weekends and holidays.
**Some codes may vary or be charged in multiple units, depending on patient-specific testing parameters.
If no cells are available for analysis, only set up fees will be billed.
Submitting a Sample
Amniotic Fluid (AF): 15-20 ml of amniotic fluid in 2-3 sterile tubes. Please use B-D syringe. Do not use: Monoject or Jelco syringes, or silicon coated tubes. AFP testing will be performed on all amniotic fluid specimens unless otherwise indicated.
– Interphase FISH: Aspirate 5 ml of amniotic fluid in addition to the 15 ml of fluid required for cytogenetics, if possible. Bloody samples are not appropriate for interphase FISH due to the increased risk of maternal cell contamination.
Chorionic Villus Sample (CVS): 10-15 mg in sterile tissue culture media.
Percutaneous Umbilical Blood (PUBS): Minimum of 1 ml peripheral blood in a preservative free sodium-heparin (green top) tube. Invert tube to mix well.
Molecular Studies: No additional sample is required. Cytogenetic analysis will be performed and amniocytes will be cultured to send to an outside laboratory for molecular studies.
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