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Test ID CMAPC Chromosomal Microarray, Autopsy, Products of Conception, or Stillbirth, Varies

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 (FISH) 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

 

Assessing regions of homozygosity related to uniparental disomy or identical by descent

Testing Algorithm

A maternal blood sample is requested when ordering this test, see PPAP / Parental Sample Prep for Prenatal Microarray Testing. The PPAP test must be ordered under a different order number than the prenatal specimen.

 

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.

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.

 

If an insufficient sample is received or MCC is identified in the prenatal sample, microarray testing will be performed on cultured material.

 

If a formalin-fixed, paraffin-embedded specimen is submitted, the test will be cancelled and CMAMT / Chromosomal Microarray, Autopsy/Products of Conception/Stillbirth, Tissue will be added and performed as the appropriate test.

 

See Frequently Asked Questions: Cytogenetic Testing of Products of Conception by Chromosomal Microarray Analysis in Special Instructions.

Method Name

Chromosomal Microarray

Reporting Name

Chromosomal Microarray, POC

Specimen Type

Varies


Advisory Information


This test does not detect balanced chromosome rearrangements such as Robertsonian or other reciprocal translocations, inversions, or balanced insertions.



Additional Testing Requirements


A maternal blood sample is requested when ordering this test (see PPAP / Parental Sample Prep for Prenatal Microarray Testing). 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.

 

If additional molecular genetic or biochemical genetic testing is needed, order CULAF / Culture for Genetic Testing, Amniotic Fluid or CULFB / Fibroblast Culture for Genetic Testing 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 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.

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

Supplies: Refrigerate/Ambient Shipping Box, 5 lb (T329)

Container/Tube: Amniotic fluid container

Specimen Volume: 20-30 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.

3. Place the tubes in a Refrigerate/Ambient Shipping Box, 5 lb.

4. Fill remaining space with packing material.

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 also 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 Solution (T132)

Container/Tube: In sterile Hank's solution


Specimen Minimum Volume

Chorionic villus: 10 mg
Muscle-fascia: 1 cm(3)

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Refrigerated 

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Specimens are processed Monday through Sunday.

Results reported Monday through Friday, 8 a.m.-5 p.m.

Performing 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. This test has not been cleared or approved by the U.S. 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 49549-9
55259 Additional Information 48767-8
55260 Released By 18771-6

NY State Approved

Yes

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 in Special Instructions:

-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) in Special Instructions (Only for products of conception or stillbirth specimen).

3. Chromosomal Microarray Prenatal Patient Information (T716) in Special Instructions

Genetics Test Information

Cultures from this specimen will be discarded 10 days after all cytogenetic test results have been reported. If further testing is desired, call the laboratory at 507-284-1668.