Chromosome Analysis, Amniotic Fluid, for Prenatal Genetic Diagnosis

WSLH Department: Cytogenetics
WSLH Test Code: 850
Availability: Monday-Friday 7:45 AM - 4:30 PM, Saturday 7:45 AM - 12:00 PM
Turn-around Time: Approximately 7-14 days, with an average of 11 days (longer for specimens with small volume, containing blood or slow growth). (Reports are issued Monday-Friday 7:45 AM - 4:30 PM)
Recommended Uses: Determination of fetal karyotype for: advanced maternal age, abnormalities observed on ultrasound examination, abnormal maternal serum screen, previous pregnancy with abnormal karyotype or parent with balanced chromosome rearrangement. May be used in conjunction with chromosomal microarray analysis (CMA) or fluorescence in situ hybridization (FISH) assays.
Additional Tests Performed:
Patient Preparations:
Specimen Requirements: 15-30 ml amniotic fluid
Specimen Handling & Transport: Store and transport specimens at room temperature (may transport with coolant during hot weather, >85 degrees F). DO NOT FREEZE. The laboratory must receive specimens within 24 hours of collection.
Collection Kit/Container:
Collection Instructions: Collect the fluid under sterile, ultrasound guided conditions using a 22-gauge needle inserted through the uterine wall and into the amniotic cavity. Discard the first 1-2ml of amniotic fluid to minimize the possibility of maternal cell contamination, and dispense 15-30 ml of the remaining fluid into two or three sterile 15 ml centrifuge tubes.
Contact the laboratory(608-262-0402) to obtain Amniotic Fluid kits.
Kits include: 2-15ml sterile conical tubes, 1 Test requisition form (#131), and 1 Biohazard bag and absorbent pad.
Unacceptable Conditions: Sample must not be frozen.
Requisition Form: Cytogenetics Lab Genetic Diagnosis Form #131
Required Information: Laboratory regulations require the following minimum information to be provided on the requisition form for a specimen to be accepted for testing: Patient name or unique identifier; date and time of collection, patient date of birth and sex, specimen type/site of collection, gestational age, test request(s), reason for referral, clinician name and UPIN/NPI, and address for reporting results. Please be certain that name/identifier on the form matches that on the specimen label.
Results Include: Result written using current International System for Human Cytogenetic Nomenclature (ISCN) and interpretation of results.
Limitations: The cytogenetic methods used in this analysis do not routinely detect small structural rearrangements, microdeletions, or low level (<20%) mosaicism. Viable cells may be maternally derived.
Additional Tests Recommended: If a structural rearrangement is observed, parental blood chromosome analysis is recommended to determine whether the abnormality is inherited or is de novo and to possibly aid in defining the chromosome rearrangement. Fluorescence in situ hybridization analysis may be recommended to characterize chromosome abnormalities; if performed there will be an additional charge.
Additional Comments: Alpha Fetoprotein quantification (Test 851) in amniotic fluid will be performed for all specimens with a gestational age between 12 and 24 weeks. Includes Acetylcholinesterase (ACHe) quantification when appropriate.
Methodology: Microscopic analysis of G-banded chromosomes.
Includes: G-banded chromosome analysis of cultured amniocytes. Includes in situ culture of cells from amniotic fluid, examination of at least 15 metaphase cells from 15 independent colonies, and preparation of two karyograms. Additional cells may be examined if indicated by initial results. Additional karyograms may be prepared if multiple cell lines are observed.
CPT Code: 88235, 88267, 88280
Price: For pricing information, please call 608-262-0402.
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