Test Details
Methodology
SNP microarray analysis is performed using the Cytoscan® HD Accel platform, which uses 743,130 SNP probes and 2,029,441 NPCN probes with a median spacing of 0.818 kb.
Result Turnaround Time
14 - 17 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.
Use
This test 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
Pertinent medical findings must accompany the test request form. Call 800-345-4363 to request forms, or photocopy the Clinical Questionnaire for SNP Microarray from the Genetics Appendix online. This test may also be performed on adults.
When a child tested with this assay is found to have an abnormal array of unknown clinical significance that may be clarified through parental testing, there will be no charge associated with the follow-up parental testing that is based on the child's results. All other parental follow-up testing will be charged, including (but not limited to) autism susceptibility regions, known microdeletions/microduplications, autosomal recessive deletions/duplications, and large copy-number changes with likely pathogenic significance. The child's abnormal array results will indicate whether parental testing will be performed at no charge and will include the appropriate parental follow-up test number. For parental follow-up testing for arrays not performed at Labcorp, call 800-345-4363 to speak to a genetic counselor.
Contact your local Labcorp branch supply department to order buccal swab kits using PeopleSoft No. 136351 or PeopleSoft No. 136352 for Purflock Labcorp buccal kits (preferred), or PeopleSoft No. 3177.
Limitations
This SNP assay does not detect balanced rearrangement, 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.
Custom Additional Information
Positive evaluation criteria include: DNA copy gain/loss within known clinically significant gene region of 50 kb or greater. DNA copy number loss >200 kb or gain >500 kb outside known clinically significant regions with at least one OMIM annotated gene or within a region of clear clinical significance. UPD testing is recommended for patient results demonstrating a long contiguous region of homozygosity in a single chromosome >20 Mb interstitially or >10 Mb telomerically (15 and 8 Mb, respectively, for imprinted chromosomes). Contiguous homozygosity >10 Mb within multiple chromosomes suggests common descent. These regions of potential recessive allele risk are designated.
Specimen Requirements
Specimen
Whole blood, DNA, or Labcorp buccal swab kit (buccal swab collection kit contains instructions for the use of a buccal swab)
Volume
4 mL or Labcorp buccal swab kit
Minimum Volume
2 mL (neonatal) (note: this volume does not allow for repeat testing) or two buccal swabs
Container
Green-top (heparin) tube (preferred), yellow-top (ACD) tube or lavender-top (EDTA) tube, DNA in 2 mL tube, Labcorp Genetic buccal swab kit, or Labcorp molecular buccal swab kit
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Quantity not sufficient for analysis; wet buccal swab; gel-separator tubes; microtainer tubes and fixed cell pellets; buccal kits with open envelopes; DNA tubes not extracted at CLIA-certified lab
References
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 510002 | Chromosome Microarray | 94087-4 | 510004 | Specimen Type | 31208-2 | |
| 510002 | Chromosome Microarray | 94087-4 | 510005 | # of Genotyping Targets | 62378-5 | |
| 510002 | Chromosome Microarray | 94087-4 | 510006 | Array Type | 62376-9 | |
| 510002 | Chromosome Microarray | 94087-4 | 510007 | Diagnosis | 62357-9 | |
| 510002 | Chromosome Microarray | 94087-4 | 510109 | Interpretation | 62357-9 | |
| 510002 | Chromosome Microarray | 94087-4 | 510035 | Director Review: | 48672-0 | |
| 510002 | Chromosome Microarray | 94087-4 | 512123 | 11502-2 | ||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 510004 | |||||
| Result Code Name | Specimen Type | |||||
| UofM | ||||||
| Result LOINC | 31208-2 | |||||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 510005 | |||||
| Result Code Name | # of Genotyping Targets | |||||
| UofM | ||||||
| Result LOINC | 62378-5 | |||||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 510006 | |||||
| Result Code Name | Array Type | |||||
| UofM | ||||||
| Result LOINC | 62376-9 | |||||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 510007 | |||||
| Result Code Name | Diagnosis | |||||
| UofM | ||||||
| Result LOINC | 62357-9 | |||||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 510109 | |||||
| Result Code Name | Interpretation | |||||
| UofM | ||||||
| Result LOINC | 62357-9 | |||||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 510035 | |||||
| Result Code Name | Director Review: | |||||
| UofM | ||||||
| Result LOINC | 48672-0 | |||||
| Order Code | 510002 | |||||
| Order Code Name | Chromosome Microarray | |||||
| Order Loinc | 94087-4 | |||||
| Result Code | 512123 | |||||
| Result Code Name | ||||||
| UofM | ||||||
| Result LOINC | 11502-2 |