Home
HelpTest ID BUCCF X and Y Aneuploidy Detection, Buccal Smear, FISH
Useful For
Diagnosis of mosaic sex chromosome aneuploidy as a supplement to conventional chromosome studies in patients with normal or uncertain chromosome results or when an alternative tissue needs to be studied.
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _PBCT | Probe, +2 | No, (Bill Only) | No |
| _PADD | Probe, +1 | No, (Bill Only) | No |
| _PB02 | Probe, +2 | No, (Bill Only) | No |
| _PB03 | Probe, +3 | No, (Bill Only) | No |
| _IL25 | Interphases, <25 | No, (Bill Only) | No |
| _I099 | Interphases, 25-99 | No, (Bill Only) | No |
| _I300 | Interphases, ≥100 | No, (Bill Only) | No |
Testing Algorithm
This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results. Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.
Special Instructions
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
X,Y Aneuploidy, Buccal Smear, FISHSpecimen Type
Buccal SwabProvide a reason for referral with each specimen. The laboratory will not delay or reject testing if this information is not provided, but appropriate testing and interpretation may be compromised.
Container/Tube: Buccal Smear Collection Kit (Supply T543)
Specimen Volume: 2 Cyto-Pak brushes
Collection Instructions:
1. Patient should rinse out mouth vigorously with mouthwash followed by water for approximately 15 seconds. Mouthwash is not a requirement but helps reduce the bacteria found in the mouth that may hinder testing.
2. Remove the Cyto-Pak brush from the container only touching the "stick" end. Save the container.
3. Using medium pressure, rotate the brush several times on the inside of the cheek.
4. Return brush to container and cap.
5. Repeat steps 2 through 4 on the other cheek using the second brush.
6. It is important that the patient's buccal cells are not contaminated with cells from any other source. Do not touch the bristles. Do not brush too vigorously. If blood appears, discard the brush and restart the collection process.
7. Label each container with patient's name and order number or hospital/clinic number.
Additional Information:
1. Provide appropriate clinical information about the patient as per specific test requirements.
2. It is important that the cells do not dry out during shipping. Ensure that the container is tightly sealed.
Forms: New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.
Specimen Minimum Volume
2 Cyto-Pak brushes
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Buccal Swab | Ambient (preferred) | |
| Refrigerated | ||
Clinical Information
Aneuploidy of the sex chromosomes is common among recognized congenital syndromes. For example, the majority (80%) of individuals with Klinefelter syndrome have 2 X chromosomes and 1 Y chromosome; the remainder are mosaics or variants. Individuals with Turner syndrome have a single X chromosome in 55% of cases; the remaining 45% are either variants or mosaics.
Conventional cytogenetic analysis should be performed for confirmation, especially when the results are abnormal.
Structural abnormalities of X and Y chromosomes will be missed by this technique, as will low-level mosaicism.
This test can detect between 50% to 70% of Turner syndrome cases (only those caused by complete lack of 1 sex chromosome [45,X] or high-level mosaicism for a 45,X). Congenital blood chromosome analysis (CMS / Chromosome Analysis, for Congenital Disorders, Blood) should always be performed for Turner syndrome. The test does not rule out numeric or structural cytogenetic anomalies involving chromosomes other than X and Y.
Reference Values
An interpretive report will be provided.
Cautions
Because this FISH test is not approved by the U.S. Food and Drug Administration, it is important to confirm any numeric X and Y chromosome abnormalities by other established methods, such as clinical history or physical evaluation.
Interfering factors:
-Excessive transport time
-Inadequate amount of specimen may not permit adequate analysis
-Improper packaging may result in broken, leaky, and contaminated specimen during transport
Day(s) Performed
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m. to 5 p.m. CST.
Report Available
8 daysPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
88271x2, 88291 – DNA probe, each (first probe set), Interpretation and report
88271x2 – DNA probe, each; each additional probe set (if appropriate)
88271x1 – DNA probe, each; coverage for sets containing 3 probes (if appropriate)
88271x2 – DNA probe, each; coverage for sets containing 4 probes (if appropriate)
88271x3 – DNA probe, each; coverage for sets containing 5 probes (if appropriate)
88274 w/modifier 52 – Interphase in situ hybridization, <25 cells, each probe set (if appropriate)
88274 – Interphase in situ hybridization, 25 to 99 cells, each probe set (if appropriate)
88275 – Interphase in situ hybridization, 100 to 300 cells, each probe set (if appropriate)