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Laboratory Test Directory

FISH Analysis for Microdeletion Syndromes


Name Method Department Units
FISH Analysis for Microdeletion Syndromes Fluorescence in situ hybridization (FISH)

Specimen Requirements

Whole blood

Container Type Container Size Specimen Volume

Green tube (Sodium heparin), No Gel

10 mL 3 mL-10 mL

Green tube (Sodium heparin), No Gel

3 mL 3 mL-5 mL

Green tube (Sodium heparin), No Gel

3 mL 1 mL-3 mL

Room temperature - 24 hour(s)

Specimen Preparation

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

Reasons for Rejection

  • Wrong collection tube
  • Frozen specimen
  • Centrifuged specimen
  • Serum sample
  • Clotted specimen


Completed Genetics Test Requisition Form is required. High resolution chromosome analysis is recommended to be done in conjunction with this testing. Testing for common chromosome microdeletion syndromes including DiGeorge/Velocardiofacial (22q11.2 deletion) syndrome, Williams syndrome, Prader-Willi/Angelman syndrome, Smith-Magenis syndrome, Miller-Dieker syndrome, Kallmann syndrome, Wolf-Hirschhorn syndrome, Cri du Chat syndrome,and steroid sulfatase deficiency (X-linked ichthyosis) STS deletion. Please specify on the Requisition Form which syndrome is suspected or which chromosome region/locus is requested for FISH analysis. Call Cytogenetics (614)722-5321 with questions or to perform testing on tissue types other than blood sample. Collect whole blood sample in sodium heparin tube (dark green-top tube without gel separator). Do NOT use lithium heparin or other types of heparin tubes; check tube for proper heparin type. FISH analysis will be performed on metaphase cells from cultured blood lymphocytes; therefore, FISH result from this testing typically takes 2-3 weeks.


Lab Form

CPT Code

  • 88273
  • 88271
  • 88230