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HelpOrder Code LABCMAMT Chromosomal Microarray, Autopsy/Products of Conception/Stillbirth, Tissue
Useful For
Diagnosis of congenital copy number changes in products of conception, including aneuploidy (ie, trisomy or monosomy) and structural abnormalities
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 previously 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, since 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
Testing Algorithm
Hematoxylin and eosin stain review of the paraffin-embedded specimen is performed to identify the area of fetal tissue prior to DNA extraction and microarray analysis.
Special Instructions
Method Name
Chromosomal Microarray (CMA)
Reporting Name
Chromosomal Microarray, POC, FFPESpecimen Type
VariesOrdering Guidance
If a fresh tissue specimen is submitted, this test will be cancelled and CMAPC / Chromosomal Microarray, Autopsy, Products of Conception, or Stillborn 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; order PPAP / Parental Sample Prep for Prenatal Microarray Testing, Blood under a different order number than the prenatal specimen. Maternal cell contamination 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. Testing will not be rejected if maternal blood is not received; however, the possibility of maternal cell contamination cannot be excluded.
A paternal blood sample is desired but not required (see PPAP / Parental Sample Prep for Prenatal Microarray Testing, Blood).
Necessary Information
A reason for testing and pathology report are required in order for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Tissue
Container/Tube: Formalin-fixed, paraffin-embedded block containing fetal or placental (including chorionic villi) tissue.
Specimen Type: Slides
Specimen Volume: 6 Consecutive, unstained, 5-micron-thick sections placed on positively charged slides and 1 hematoxylin and eosin-stained slide.
Specimen Minimum Volume
Formalin-fixed, paraffin-embedded tissue block; 5 Consecutive, unstained slides and 1 hematoxylin and eosin-stained slide
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 paraffin-embedded 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.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
81229
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. Chromosomal Microarray Prenatal and Products of Conception Information (T716)