Test ID: FPOC
Aneuploidy Detection, Products of Conception (POC), FISH
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Screening for the common chromosomal aneuploidies (13, 15, 16, 18, 21, 22, X, and Y) in POC when fresh tissue is not available for full chromosome analysis
Rapid detection of common chromosomal aneuploidies or triploidy
Determining the genetic cause of a miscarriage
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
If chromosome analysis on products of conception is not successful, this FISH test will be run automatically.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Fluorescence In Situ Hybridization (FISH) with DNA Probes
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
FISH for POC
FISH for stillbirth
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Provide a reason for referral 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.
Specimen Type: Tissue block
Collection Instructions: Submit formalin-fixed, paraffin-embedded tissue block containing fetal or placental (including chorionic villi) tissue.
Additional Information: Do not send the entire fetus.
Forms:
1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.
2. If not ordering electronically, submit a Cytogenetics/AFP Congenital Disorders Request Form (Supply T238) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Tissue | Ambient (preferred) | |
| Refrigerated | ||
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Products of conception (POC) are tissues created at conception that spontaneously miscarry; these tissues include chorionic villi, fetal membranes, or fetal tissue. Spontaneous miscarriages occur in 15% to 20% of all recognized human conceptions. While there are many possible causes for miscarriages, chromosome anomalies can be identified in up to 50% of first-trimester miscarriages. It is important to determine a possible chromosomal cause of the pregnancy loss as this information impacts patient management and facilitates understanding of the reason for the loss.
Chromosomal aneuploidy, the gain or loss of chromosomes, is a major cause of early fetal demise. Trisomy is the most common type of chromosome abnormality in spontaneous abortions and has been observed for most chromosomes, with 13, 15, 16, 18, 21, 22, X, and Y being the most common.
Conventional chromosome analyses of POC (#8887 Chromosome Analysis, Autopsy, Products of Conception, or Stillbirth) is a commonly performed method used to identify these common chromosome aneuploidies. Conventional chromosome analysis involves fibroblast cultures. Unfortunately, 20% of POC specimens fail to grow when cultured. A FISH method has been developed to analyze this subset of cases or to be used when fresh tissue is not available for full chromosome analysis.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Interpretation Provides information to assist in interpretation of the test results
Aneuploidy is detected when the percent of cells with an abnormality exceeds the normal reference range for any given probe.
An interpretive report is provided.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test has not been approved by the FDA and is best used as an adjunct to existing clinical and pathological information.
Supportive Data
The specificity of these probes is estimated to be 100% with no cross hybridizations. To establish the analytic sensitivity, analysis was based on 37 products of conception specimens. Chromosome analysis was unsuccessful for 8 of the 37 specimens. For the remaining 29 cases, the correct FISH result was obtained when compared to chromosome analysis.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Warburton D, Byrne J, Canki N: Chromosome anomalies and prenatal development: An atlas. In Oxford Monographs on Medical Genetics. New York, Oxford University Press, 1991, pp 2-3, 57-62
Method Description Describes how the test is performed and provides a method-specific reference
This FISH test uses commercially available chromosome-specific fluorescent-labeled DNA probes for FISH. The 3 probe combinations utilized include: centromere probes for chromosome X (DXZ1) in green, Y (DYZ3) in orange, and 18 (D18Z1) in aqua; locus-specific probes for chromosomes 13 at 13q14 in green and 21 (D21S259, D21S341, D21S342) at 21q22.13-q22.2 in orange; a centromere probes for chromosome 16 (D16Z3) in aqua and chromosome 15 (D15Z4) in orange and a locus-specific probe for chromosome 22 (BCR) at 22q11.2 in green. The above centromere probes hybridize to the alpha-satellite DNA regions.
Formalin-fixed, paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. Two slides are prepared with 2 hybridization sites per slide. Each probe set is hybridized to a separate hybridization site. For each probe, 200 interphase nuclei are scored and results for each abnormal probe(s) are expressed as percent abnormal nuclei. Aneuploidy of chromosomes 13, 15, 16, 18, 21, 22, X, and/or Y is reported. (Unpublished Mayo method)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
88271 x 8-DNA probe, each
88275-Interphase in situ hybridization
88291-Interpretation and report
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 22363 | Specimen | 31208-2 |
| 22364 | Specimen ID | N/A |
| CG239 | Source | N/A |
| 22366 | Order Date | N/A |
| CG241 | Reason For Referral | 42349-1 |
| 22367 | Method | In Process |
| 22369 | Results | In Process |
| 22370 | Interpretation | 69965-2 |
| 22371 | Amendment | In Process |
| 22372 | Consultant | N/A |
| 22373 | Report Date | N/A |
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