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Laboratory Test Directory

SNP Microarray Analysis (Chromosomal Microarray)

Components

Name Method Department Units
SNP Microarray Microarray analysis
Cytogenetics

Battery Members

Reflexes to FISH analysis if needed. Parental blood specimens may be requested in some cases.

Specimen Requirements

Whole blood

Container Type Container Size Specimen Volume
Required

Purple tube (EDTA)

4 mL 4 mL
Required

Green tube (Sodium heparin), No Gel

3 mL 3 mL
Stability

Room temperature - 48 hour(s)
Refrigerated - 72 hour(s)

Specimen Preparation

  • Do not centrifuge
  • Do not freeze
  • Keep at room temperature or refrigerate

Reasons for Rejection

  • Frozen specimen
  • Centrifuged specimen
  • Not all required tubes submitted
  • Wrong collection tube
  • Clotted specimen

Comments

Please click on the Lab Form Link in the Forms Section to print and complete the Genetic Test Requisition Form. Submission of completed Genetic Test Requisition Form is required, and submission of informed consent form is recommended. Microarray evaluates DNA copy number across the genome at higher resolution than routine chromosome analysis. It can detect submicroscopic genomic imbalances not detectable by routine chromosome analysis, as well as large imbalances detectable by routine chromosome analysis. 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 genetic disorders. Evidence suggestive of a blood relationship between the parents (parental consanguinity) also may be revealed. This chromosomal microarray analysis uses oligonucleotide probes as well as SNP probes. DNA copy number abnormality detection is done by comparative genomic hybridization (CGH) analysis using ~135,000 oligonucleotide probes, and ROH detection analysis is done by SNP analysis using ~67,000 SNP probes. For additional information, please refer to the Chromosomal Microarray (CGH+SNP) information sheet. Submission of whole blood in both EDTA tube AND sodium heparin (NaHep) tube is required. If parental consanguinity is known, please provide reported parental relationship information onthe requisition form. PLEASE NOTE: microarray analysis may not be able to detect the presence of mosaism if abnormality is present in less than 30% of cells.

Forms

Lab Form

CPT Code

  • 81229