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HelpTest Code LAB7043 Chromosomal Microarray, Autopsy, Products of Conception, or Stillbirth
Additional Codes
SQ: CMAPCM
MAYO: CMAPC
Useful For
Prenatal diagnosis of copy number changes (gains or losses) across the entire genome
Diagnosing chromosomal causes for fetal death
Determining recurrence risk of future pregnancy losses
Determining the size, precise breakpoints, gene content, and any unappreciated complexity of abnormalities detected by other methods, such as conventional chromosome and fluorescence in situ hybridization studies
Determining if apparently balanced abnormalities identified by previous conventional chromosome studies have cryptic imbalances, as a proportion of such rearrangements that appear balanced at the resolution of a chromosome study are actually unbalanced when analyzed by higher-resolution chromosomal microarray
Assessing regions of homozygosity related to uniparental disomy or identical by descent
Testing Algorithm
Maternal cell contamination (MCC) testing will be performed at no additional charge on the maternal blood and fetal tissue to rule out the presence of maternal cells in the product of conception sample. For more information see Additional Testing Requirements. If an insufficient specimen is received or MCC is identified in the prenatal specimen, microarray testing will be performed on cultured material.
Special Instructions
Method Name
Chromosomal Microarray (CMA)
Reporting Name
Chromosomal Microarray, POCSpecimen Type
VariesOrdering Guidance
This test does not detect balanced chromosome rearrangements, such as Robertsonian or other reciprocal translocations, inversions, or balanced insertions.
If a formalin-fixed, paraffin-embedded specimen is submitted, the test will be canceled and CMAMT / Chromosomal Microarray, Autopsy/Products of Conception/Stillbirth, Tissue will be added and performed as the appropriate test.
For answers to frequently asked questions and more information, see Pregnancy loss on MayoClinicLabs.com.
Additional Testing Requirements
A maternal blood sample is requested when ordering this test (see PPAP / Parental Sample Prep for Prenatal Microarray Testing, Blood). Testing will not be rejected if maternal blood is not received; however, the possibility of maternal cell contamination cannot be excluded. The PPAP test must be ordered under a different order number than the prenatal specimen.
A paternal blood sample is desired but not required, see PPAP / Parental Sample Prep for Prenatal Microarray Testing, Blood.
If additional molecular genetic or biochemical genetic testing is needed, order CULAF / Culture for Genetic Testing, Amniotic Fluid or CULFB / Fibroblast Culture for Biochemical or Molecular Testing, Chorionic Villi/Products of Conception/Tissue so that cultures may be set up specifically for use in these tests.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. Provide a reason for testing with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.
2. Notify the laboratory if the pregnancy involves an egg donor or gestational carrier.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Products of conception or stillbirth
Supplies: Hank's Solution (T132)
Container/Tube: Sterile container with sterile Hank's solution, Ringer's solution, or normal saline
Specimen Volume: 1 cm(3) of placenta (including 50-mg chorionic villi) and 1 cm(3) biopsy specimen of muscle/fascia from the thigh
Collection Instructions:
1. Attempt to identify and send only fetal tissue for analysis.
2. If a fetus cannot be specifically identified, collect 50-mg villus material or tissue that appears to be of fetal origin.
3. If multiple specimen types are sent, send each specimen in a separate container. Multiple specimens received (eg, placenta and fetal thigh) will be ordered under 1 test. All specimens will be processed separately.
Additional Information:
1. Do not send entire fetus.
2. While fresher specimens prepared as described above are preferred, we can attempt analysis on specimens that have been in less-than-ideal conditions.
Specimen Type: Autopsy
Supplies: Hank's Solution (T132)
Container/Tube: Sterile container with sterile Hank's solution, Ringer's solution, or normal saline
Specimen Volume: 1 cm(3) biopsy specimen of muscle/fascia from the thigh
Collection Instructions:
1. Wash biopsy site with an antiseptic soap.
2. Thoroughly rinse area with sterile water.
3. Do not use alcohol or iodine preparations.
4. Biopsy specimens are best taken by punch biopsy to include full thickness of dermis.
Specimen Type: Amniotic fluid
Container/Tube: Amniotic fluid container
Specimen Volume: 20 to 30 mL
Collection Instructions:
1. Optimal timing for specimen collection is during 14 to 18 weeks of gestation, but specimens collected at other weeks of gestation are also accepted. Provide gestational age at the time of amniocentesis.
2. Discard the first 2 mL of amniotic fluid.
Additional Information:
1. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.
2. Bloody specimens are undesirable.
3. Results will be reported and telephoned or faxed if requested.
Specimen Type: Chorionic villus
Supplies: CVS Media (RPMI) and Small Dish (T095)
Container/Tube: 15-mL tube containing 15 mL of transport media
Specimen Volume: 50 mg
Collection Instructions:
1. Collect chorionic villus specimen (CVS) by transabdominal or transcervical method.
2. Transfer CVS to a Petri dish containing transport medium (such as CVS Media [RPMI] and Small Dish).
3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of villi and remove any blood clots and maternal decidua.
Acceptable
Specimen Type: Cultured cells
Container/Tube: T25 flasks with culture media
Specimen Volume: 2 T25 flasks
Specimen Type: Tissue
Supplies: Hank's Solution (T132)
Container/Tube: In sterile Hank's solution
Specimen Minimum Volume
Chorionic villus: 10 mg; Muscle-fascia: 1 cm(3); Other specimen types: See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Method Description
DNA extracted from either autopsy, products of conception, or stillbirth samples is labeled and hybridized to the microarray. Following hybridization, the microarray is scanned, and the intensity of signals is measured and compared to a reference data set. These data are used to determine copy number changes and regions of excess homozygosity. Chromosomal microarray data alone does not provide information about the structural nature of an imbalance, and some abnormal results may be characterized by fluorescence in situ hybridization, limited chromosome analysis, or additional techniques.(Unpublished Mayo method)
Day(s) Performed
Monday through Sunday
Report Available
10 to 25 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81229
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CMAPC | Chromosomal Microarray, POC | 94087-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 55253 | Result Summary | 86611-1 |
| 55254 | Result | 62356-1 |
| 55255 | Nomenclature | 62378-5 |
| 55256 | Interpretation | 62357-9 |
| CG945 | Reason for Referral | 42349-1 |
| CG946 | Specimen | 31208-2 |
| 55257 | Source | 48002-0 |
| 55258 | Method | 85069-3 |
| 55259 | Additional Information | 48767-8 |
| 55260 | Released By | 18771-6 |
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Final Disposition of Fetal/Stillborn Remains if fetal specimen is sent. Only for products of conception or stillbirth specimens.
3. Chromosomal Microarray Prenatal and Products of Conception Information (T716)
Secondary ID
63042Genetics Test Information
Cultures from this specimen will be discarded 10 days after all cytogenetic test results have been reported. If additional testing is desired, call the laboratory at 800-533-1710.