Ordering Recommendation
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- Preferred collection times are Monday , Tuesday and Friday
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Specimen Requirements
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| Type | - Peripheral blood/ whole blood
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| Container | |
Collection Procedure
| - Invert several times to mix
- Other anticoagulants are not recommended since they are harmful to the viability of the cells
- Specimen must be accompanied by a completed test requisition
- Failure to include relevant patient information may result in test results being delayed or discontinued
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| Required Volume | - Optimal Volume: 5-7 ml
- Minimum Volume: 1 ml for neonates; 2 ml for all other patients
(Submitting
the minimum volume makes it impossible to repeat the test or perform
confirmatory/reflex testing. In some situations, a minimum volume may
require a second collection.) - Pediatric Volume: 1-3 ml of peripheral blood or cord blood
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| Stability/Storage | - Specimens are to be kept and delivered at room temperature
- Do not freeze specimen or expose to extreme heat
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| Grounds for Rejection | |
Testing Information |
| Availability | - Specimens are received in the Cytogenetics Laboratory weekdays from 8:00 a.m. to 5:00 p.m.
- Cultures are routinely initiated Mondays, Tuesdays and Fridays. Neonate cultures can be initiated on other days.
- There is a Cytogenetics technologist on call Saturday, Sunday and statutory holidays from 8:30 a.m. to 5:00 p.m. for urgent specimens only. This person can be reached through Royal University Hospital Switchboard (655-1000)
- Specimens to be received the day before a long weekend or during the Christmas/ New Year or Easter Holidays must be approved with the Laboratory before sending
- Booking of specimens from outside the Saskatoon Health Region is recommended for tracking purposes
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| Testing Site | Cytogenetics Laboratory
Ellis Hall Ground Floor, Room 35
Royal University Hospital, 103 Hospital Drive
Saskatoon SK S7N 0W8
Phone: 306-655-1706
FAX: 306-655-6462 |
| Results Reporting | - Dependent on specimen type, indication and workload
- STAT and urgent specimens are reported within 14 days
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Reflex Testing
| - National guidelines require a concurrent chromosome analysis in most cases
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| Methodology | - PHA-stimulated lymphocyte culture and fluorescence in situ hybridization (FISH) with commercially available probes
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Clinical Interpretation
| - Diagnosis of microdeletion syndromes
- Anomaly designation follows the most recent edition of the International System for Human Cytogenetic Nomenclature
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Specimen Retention
| - Original peripheral blood specimen: two weeks
- Cell suspension: two months after reporting
- FISH slide(s): six months
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| Alternate Test Names | |
Additional Comments
| - The test is not appropriate for acquired hematological disorders (see Chromosome analysis – Bone Marrow)
- Molecular genetics (DNA) testing is only done through referral to Medical Genetics (phone: 655-1692)
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| Reference Ranges | - Two copies of the probe at the expected chromosome location
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Testing Ordering Requirements |
Forms Required
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Patient History |
Relevant Clinical History
| - Clinical features of Wolf-Hirschhorn, Cri-du-chat, Williams, Smith-Magenis, Miller-Dieker, DiGeorge/ Velocardiofacial, Kallman syndromes; lchthyosis or Steroid Sulfatase deficiency
- Clinical features of Prader-Willi or Angelman syndrome after testing for imprinting of the 15q11.2 chromosomal region
- SRY study in some disorders of sexual development
- Parental study in cases with a positive diagnosis
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