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Laboratory Test Directory

POC Microarray with 5-Cell Chromosome Analysis

Components

Name Method Department Units
POC Microarray with 5-Cell Chromosome Analysis DNA extraction
Microarray analysis
Cell Culture
Chromosomal analysis
Cytogenetics

Specimen Requirements

Whole blood

Container Type Container Size Specimen Volume
Preferred

Purple tube (EDTA)

6 mL 3 mL- 6 mL
Stability

Room temperature - 24 hour(s)
Refrigerated - 72 hour(s)

Specimen Preparation

  • Keep at room temperature or refrigerate

Tissue (Fresh)

Container Type Container Size Specimen Volume
Preferred

Tissue culture transport media

N/A 1 cm cube or greater
Alternate

Sterile container with saline

N/A 1 cm cube or greater
Stability

Room temperature - 24 hour(s)
Refrigerated - 48 hour(s)

Specimen Preparation

  • Keep at room temperature or refrigerate
  • Transport to the lab immediately after collection
  • Do not freeze
  • Do not formalin fix the sample

Reasons for Rejection

  • Inadequate tissue
  • Delayed or improper handling
  • Wrong type of specimen
  • Tissue degradation
  • Formalin Fixed Tissue

Comments

Submission of a completed POC Genetic Test Requisition Form is required. To obtain a requisition form, please call Cytogenetics lab at (614) 722-5321. Submission of maternal blood speicmen (4mL EDTA) is strongly recommended to evaluate for maternal cell contamination of the submitted POC specimen. If the mother and the father of pregnancy are known to be consanguineous, please provide reported parental relationship information on the requisition form.

This test inlcudes Microarray Analysis and 5-Cell Chromosome Analysis (5-Cell Abbreviated Karyotype) performed on products of conception (POC) tissue specimen. If maternal blood specimen is submitted, then maternal cell contamination study will automatically be performed. The number of chromosomes will be evaluated in 5 cultured cells and the full karyotype analysis will be performed on 1 of the 5 cells.

Fresh tissue specimen from the POC is required for this test. If return of tissue sample is desired, please indicate the tissue return request on the test requisition form as well as return shipping address, contact person name and phone number. If only frozen or formalin-fixed sample is available, please call the laboratory (614) 722-5321 to speak with a laboratory genetic cousnelor to discuss alternative test options.


While many factors contribute to pregnancy loss and fetal demise (including maternal conditions, environmental exposures, and fetal abnormalities), a chromosome abnormality is present in greater than 50% of first trimester losses and about 20% of second-trimester losses. Determining the cause of a loss could have important implications for evaluating recurrence risk for future pregnancies and future obstetrical management. Microarray analysis can be used as a companion test to chromosome analysis on POC specimens (chromosome analysis is normal, but the case history or pathology findings warrant further investigation;) or as a replacement test (if chromosome analysis cannot be performed due to culture failure or other reasons).

This chromosomal (whole genome) microarray analysis uses a combination of oligonucleotide probes as well as SNP probes. Detection of DNA copy number abnormalities is performed by comparative genomic hybridization (CGH) analysis using ~135,000 oligonucleotide probes, while detecton of the regions of homozygosity (ROH, also known as long contiguous stretch of homozygosity) is done by single nucloeotide polymorphism (SNP) analysis using ~67,000 SNP probes.

Chromosomal microarray analysis evaluates DNA copy number across the genome at higher resolution than chromosome analysis. It can detect submicroscopic genomic losses and gains not detectable by chromosome analysis, as well as large genomic losses and gains that are detectable by chromosome analysis (such as trisomies, monosomies, triploidy, unbalanced translocations, and unbalanced inversions). Chromosomal microarrays that incorporate single nucleotide polymorphism (SNP) probes can detect large regions of homozygosity (ROH). Presence of ROH is not diagnostic of any disorder, but it can suggest increased risk for two different classes of genetic disorders: disorders of imprinting (uniparental disomy; UPD) and recessive disorders. Evidence suggestive of a blood relationship between the parents (parental consanguinity) also may be revealed.

PLEASE NOTE: 

  • Microarray analysis may not be able to detect the presence of mosaism if abnormality is present in less than 30% of cells. Microarray analysis also cannot detect balanced chromosomal rearrangements such as a balanced translocation or inversion.
  • Due to the limited number of cells evaluated by this study for chromosome analysis, mosaicism for chromosomal abnormality may not be detected by this study. If mosaicism is suspected, an alternate testing "Tissue Chromosome Analysis (test code: TCS)" that evaluates 20 cells is available, with an option for "Mosaicism Study" that evaluates 50 cells.

CPT Code

  • 88233
  • 88261
  • 81229