Test Details
Methodology
Five-cell G-Band Chromosome analysis. SNP microarray analysis is performed using the Cytoscan® HD platform, which uses more than 743,000 SNP probes and 1,953,000 NPCN probes with a median spacing of 0.88 kb.
Result Turnaround Time
10 - 21 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
DNA extraction; interpretation; limited five-cell amniotic sample chromosome analysis (two analyses, one karyotype)
Use
The test allows prenatal detection of chromosomal aneuploidy, and is used to rule out tetraploidy and rearrangements not detected by array, such as balanced translocations and inversions. It also helps to clarify array abnormalities to determine if a structural rearrangement, marker, or isochromosome is present. Array can only provide copy number imbalances and cannot determine structure of an abnormality. The SNP assay will detect chromosomal imbalances that could be associated with developmental delay/congenital anomalies. It provides detection of possible uniparental disomy of any chromosome, the percent and location of homozygosity, including the degree of identity by descent.
Special Instructions
A completed Clinical Questionnaire for SNP Microarray should accompany specimens. Call 800-345-4363 to request the appropriate form, or photocopy the form from the Genetics Appendix online.
Concurrent maternal contamination (MCC) studies are required.
If prior NIPT studies have been performed, include copy of the report.
If specimens from a twin pregnancy are submitted by request it can be reported if these are DZ or MZ twins.
Limitations
This SNP assay does not detect balanced rearrangements, low-level mosaicism (<10%), marker chromosomes that only contain heterochromatin or tetraploidy.
This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Amniotic fluid (for direct array and abbreviated amnio chromosome analysis)
Gender by ultrasound is required. Please submit maternal blood (sodium heparin or EDTA) for maternal cell contamination (MCC) studies.
If the specimen does not meet minimum DNA quality and quantity requirements, array testing will be performed on cultured material. If cultures are needed, additional days will be required to complete testing. A notification will be sent to the client if cultures are necessary.
Volume
25 mL amniotic fluid for concurrent array and chromosome analysis
Minimum Volume
12 mL amniotic fluid (minimum volume may delay results; cells would need to be cultured for microarray analysis)
Container
Sterile plastic conical tube
Collection Instructions
Discard first 2 mL of fluid aspirated to avoid maternal cell contamination. Specimen is collected in a 20-mL sterile syringe and transferred aseptically to sterile tubes to be transported to LabCorp.
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Quantity not sufficient for analysis (<12 mL of amniotic fluid or DNA quantity <20 ng/μL); bloody sample; gestational age <17 weeks
References
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 511590 | Amnio Chrom 5 Cnt + CMA | 052182 | Cells Counted | 64095-3 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052184 | Colonies | 64096-1 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052185 | Cells Analyzed | 64092-0 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052186 | Cells Karyotyped | 64091-2 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052187 | GTG Band Resolution Achieved | 64093-8 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052188 | Cytogenetic Diagnosis | 33773-3 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052037 | Cytogenetic Interpretation | 64094-6 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052191 | Specimen Type | 31208-2 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 052038 | Director Review: | 48672-0 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 512123 | 11502-2 | |||
| 511590 | Amnio Chrom 5 Cnt + CMA | 510103 | Specimen Type | 31208-2 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 510104 | # of Genotyping Targets | N/A | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 510105 | Array Type | N/A | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 510106 | Diagnosis | 48000-4 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 510107 | Interpretation | 62365-2 | ||
| 511590 | Amnio Chrom 5 Cnt + CMA | 510108 | Director Review | 48672-0 | ||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052182 | |||||
| Result Code Name | Cells Counted | |||||
| UofM | ||||||
| Result LOINC | 64095-3 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052184 | |||||
| Result Code Name | Colonies | |||||
| UofM | ||||||
| Result LOINC | 64096-1 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052185 | |||||
| Result Code Name | Cells Analyzed | |||||
| UofM | ||||||
| Result LOINC | 64092-0 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052186 | |||||
| Result Code Name | Cells Karyotyped | |||||
| UofM | ||||||
| Result LOINC | 64091-2 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052187 | |||||
| Result Code Name | GTG Band Resolution Achieved | |||||
| UofM | ||||||
| Result LOINC | 64093-8 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052188 | |||||
| Result Code Name | Cytogenetic Diagnosis | |||||
| UofM | ||||||
| Result LOINC | 33773-3 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052037 | |||||
| Result Code Name | Cytogenetic Interpretation | |||||
| UofM | ||||||
| Result LOINC | 64094-6 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052191 | |||||
| Result Code Name | Specimen Type | |||||
| UofM | ||||||
| Result LOINC | 31208-2 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 052038 | |||||
| Result Code Name | Director Review: | |||||
| UofM | ||||||
| Result LOINC | 48672-0 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 512123 | |||||
| Result Code Name | ||||||
| UofM | ||||||
| Result LOINC | 11502-2 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 510103 | |||||
| Result Code Name | Specimen Type | |||||
| UofM | ||||||
| Result LOINC | 31208-2 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 510104 | |||||
| Result Code Name | # of Genotyping Targets | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 510105 | |||||
| Result Code Name | Array Type | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 510106 | |||||
| Result Code Name | Diagnosis | |||||
| UofM | ||||||
| Result LOINC | 48000-4 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 510107 | |||||
| Result Code Name | Interpretation | |||||
| UofM | ||||||
| Result LOINC | 62365-2 | |||||
| Order Code | 511590 | |||||
| Order Code Name | Amnio Chrom 5 Cnt + CMA | |||||
| Order Loinc | ||||||
| Result Code | 510108 | |||||
| Result Code Name | Director Review | |||||
| UofM | ||||||
| Result LOINC | 48672-0 |