• Test Code:
    8080
  • Department:
    Cancer FISH Constitutional FISH
  • Test Synonyms:
    X/Y Chimerism
  • CPT Code(s):
    882718827588368 (FFPE)
Background:

The X/Y chromosome centromere probe set is used as an adjunct to standard cytogenetic analysis for identifying and enumerating the X and Y chromosomes via fluorescence in situ hybridization (FISH) in interphase nuclei and in metaphase spreads.  The assay is appropriate to evaluate engraftment success in recipients of sex mismatched bone-marrow transplantation by determining the proportion of XX or XY donor cells.  The probe set is also used to investigate constitutional sex chromosome mosaicism in patients with Turner syndrome or Klinefelter syndrome.

Methodology:

Slides are prepared per standard protocols and 100-200 interphase cells are scored.
*Please note: it is our laboratory policy to analyze at least one metaphase cell in an interphase FISH study, if possible, including both normal and abnormal cells if both exist.

Specimen Requirements:

  • FFPE Slides: Specimen Requirements:
    • If sending slides, please include H&E stained slide cut from same block
    • Preferred slice thickness is 4-5 microns on positively charged slides. 
    • Please submit 3-5 slides.  Store at room temperature.
    • Contact Client Services at (855) 535-1522 for shipping supplies and instructions
  • Bone Marrow:  Shortly before aspiration add 0.2 cc of Sodium Heparin (1,000 units/ml) to tube of transport medium (please contact lab to arrange for transport medium to be sent).  Add at least 1 cc of bone marrow aspirate to the tube and suspend well.  Allow no clots to form.
  • Bone marrow smears:  Provide 10 slides
  • Blood:   May be used if bone marrow is inaspirable and blasts (.5%) are present.  Send in Sodium Heparin tube.
    • Adult - 3-5 mL drawn into a GREEN top sodium heparin vacutainer tube or into a pre-heparinized plastic syringe (use 0.2 cc sodium heparin, 1000 unit/mL).  Do NOT use lithium heparin.
    • Child - 1-2 mL, as above.
    • Infant - 1-2 mL, as above. 
    • Keep at room temperature and transport to laboratory as soon as possible.
    • Contact Client Services at (855) 535-1522 for supplies and instructions.
  • Bone core biopsy: May also provide cells in cases where marrow is severely packed.  Send in transport medium with Sodium Heparin.
  • Lymph node or tumor: Tumor specimens of at least 0.5 cm3 (up to 3 inches in diameter) are immediately collected with sterile methods into closable containers with sterile transport medium.* Needle biopsies will be accepted, but are often difficult to grow.  Deliver the specimen in transport medium to the laboratory within a day, if possible, with decreased success rates as specimens are delayed in transit.  Protect sample from temperature extremes during shipping.

*Sterile Ringer’s solution, either lactated or non-lactated and sterile isotonic saline are alternatives, if no complete RPMI is available.  Contact Client Services for more information on media requirements.

It is preferable to collect the specimen before initiation of chemotherapy in the patient.  Tumor samples should be selected from viable areas, with as little normal or necrotic material as possible. 

Unacceptable specimens are acellular, necrotic specimens, septic specimens, specimens in fixative or frozen, or specimens collected more than one week previously.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please provide detailed clinical information.

Test Performed (Days):

Mon - Sat

Turn Around Time:

5-10 days: Contact Lab at 855-KDL-1LAB (535-1522) - Time varies depending on number and type of tests performed.

Shipment Sensitivity Requirements:

  • Keep specimen at room temperature during transit. 
  • Do not use the cold pack provided in the KDL shipping kit. 
  • Ship the specimen overnight express, using the FedEx priority overnight label provided. 
  • The specimen must arrive at the lab no more than 24 hours after collection.

References:

Additional Info: