Test Catalog

Test Id : DD22F

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22q11.2 Deletion/Duplication, FISH, Varies

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Establishing a diagnosis of 22q deletion/duplication syndromes

 

Detecting cryptic rearrangements involving 22q11.2 or 22q11.3 that are not demonstrated by conventional chromosome studies

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial 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
_ML10 Metaphases, 1-9 No, (Bill Only) No
_M30 Metaphases, >=10 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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 application of 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
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Fluorescence In Situ Hybridization (FISH)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

22q11.2 Deletion/Duplication, FISH

Aliases
Lists additional common names for a test, as an aid in searching

22q Deletion Syndrome

22q Duplication Syndrome

DiGeorge Syndrome

Velo-Cardio-Facial Syndrome (VCFS)

TUPLE1

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 application of 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.

Specimen Type
Describes the specimen type validated for testing

Varies

Shipping Instructions

Advise Express Mail or equivalent if not on courier service.

Necessary Information

Provide a reason for referral with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
CG669 Reason for Referral
CG670 Specimen

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Submit only 1 of the following specimens:

 

Supplies: Refrigerate/Ambient Shipping Box, 5 lb (T329)

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20-25 mL

Collection Instructions:

1. Optimal timing for specimen collection is during 14 to 18 weeks of gestation, but specimens collected at other weeks of gestation are also accepted. Provide gestational age at the time of amniocentesis.

2. Discard the first 2 mL of amniotic fluid.

3. Place the tubes in a Refrigerate/Ambient Shipping Box, 5 lb (T329).

4. Fill remaining space with packing material.

Additional Information:

1. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.

2. Bloody specimens are undesirable.

3. If the specimen does not grow in culture, you will be notified within 7 days of receipt.

4. Results will be reported and also telephoned or faxed, if requested.

 

Supplies: Hank's Solution (T132)

Specimen Type: Autopsy

Container/Tube: Sterile container with sterile Hank's solution (T132), Ringer's solution, or normal saline

Specimen Volume: 1 cm(3) biopsy specimen of muscle/fascia from the thigh

Collection Instructions:

1. Wash biopsy site with an antiseptic soap.

2. Thoroughly rinse area with sterile water.

3. Do not use alcohol or iodine preparations.

4. Biopsy specimens are best taken by punch biopsy to include full thickness of dermis.

 

Specimen Type: Blood

Container/Tube: Green top (sodium heparin)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Other anticoagulants are not recommended and are harmful to the viability of the cells.

 

Supplies: CVS Media (RPMI) and Small Dish (T095)

Specimen Type: Chorionic villi

Container/Tube: 15-mL tube containing 15 mL of transport media

Specimen Volume: 20-25 mg

Collection Instructions:

1. Collect specimen by the transabdominal or transcervical method.

2. Transfer chorionic villi to a Petri dish containing transport medium (Such as CVS Media (RPMI) and Small Dish [T095]).

3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of the villi and remove any blood clots and maternal decidua.

 

Specimen Type: Fixed cell pellet

Container/Tube: Sterile container with a 3:1 fixative (methanol:glacial acetic acid)

Specimen Volume: Entire specimen

 

Supplies: Hank's Solution (T132)

Specimen Type: Products of conception or stillbirth

Container/Tube: Sterile container with sterile Hank's solution (T132), Ringer's solution, sterile RPMI transport media, or normal saline

Specimen Volume: 1 cm(3) of placenta (including 20 mg of chorionic villi) and a 1-cm(3) biopsy specimen of muscle/fascia from the thigh

Collection Instructions If a fetus cannot be specifically identified, collect villus material or tissue that appears to be of fetal origin.

Additional Information: Do not send entire fetus.

 

Supplies: Hank's Solution (T132)

Specimen Type: Skin biopsy

Container/Tube: Sterile container with sterile Hank's solution (T132), Ringer's solution, or normal saline

Specimen Volume: 1-cm(3) biopsy specimen of muscle/fascia from the thigh

Collection Instructions:

1. Wash biopsy site with an antiseptic soap.

2. Thoroughly rinse area with sterile water.

3. Do not use alcohol or iodine preparations.

4. A local anesthetic may be used.

5. Biopsy specimens are best taken by punch biopsy to include full thickness of dermis.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Final Disposition of Fetal/Stillborn Remains (if fetal specimen is sent) in Special Instructions (Only for products of conception or stillbirth specimen).

3. If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

Amniotic Fluid: 5 mL; Autopsy, Skin Biopsy: 4 mm; Blood: 2 mL; Chorionic Villi: 5 mg; Fixed Cell Pellet: 1 pellet; Products of Conception: 1 cm(3)

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Refrigerated (preferred)
Ambient

Useful For
Suggests clinical disorders or settings where the test may be helpful

Establishing a diagnosis of 22q deletion/duplication syndromes

 

Detecting cryptic rearrangements involving 22q11.2 or 22q11.3 that are not demonstrated by conventional chromosome studies

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 application of 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.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The 22q deletion syndrome and 22q duplication syndrome have overlapping phenotypes. Deletions of 22q are associated with DiGeorge and velocardiofacial syndrome. These syndromes are manifested by the presence of growth deficiency, global developmental delay, heart defect, and hearing loss. The major birth defects include palatal clefting or insufficiency and thymus aplasia. Prominent facial features are widely spread eyes, superior placement of eyebrows, downward slanting palpebral fissures with or without ptosis (droopy upper eyelid), mild micrognathia (small jaw), and a long, narrow face.

 

FISH studies are highly specific and do not exclude other chromosome abnormalities.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

Any individual with a normal signal pattern in each metaphase is considered negative for this probe.

 

Any patient with a FISH signal pattern indicating loss of the critical region (1 signal) will be reported as having a deletion of the region tested by this probe. This is consistent with a diagnosis of 22q deletion syndrome.

 

Any patient with a FISH signal pattern indicating duplication of the critical region (3 signals) will be reported as having a duplication of the region tested by this probe. This is consistent with a diagnosis 22q duplication syndrome.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test may fail to detect very small deletions within 22q11.2 or very distal deletions of chromosome 22 at 22q13.3.

 

Because this FISH test is not approved by the US Food and Drug Administration, it is important to confirm 22q deletion/duplication syndrome diagnoses by other established methods, such as clinical history or physical evaluation.

 

Interfering factors:

-Cell lysis caused by forcing the blood quickly through the needle

-Use of an improper anticoagulant or improperly mixing the blood with the anticoagulant

-Excessive transport time

-Inadequate amount of specimen may not permit adequate analysis

-Improper packaging may result in broken, leaky, and contaminated specimen during transport.

-Exposure of the specimen to temperature extremes (freezing or greater than 30 degrees C) may kill cells and interfere with attempts to culture cells.

-In prenatal specimens, a bloody specimen may interfere with attempts to culture cells and contamination by maternal cells may cause interpretive problems

Supportive Data

FISH analysis was performed on a series of patients and results were compared to cytogenetic analyses and the patient's phenotype. Using a probe for the critical region locus (HIRA), FISH analysis of metaphase cells or interphase nuclei identified HIRA deletions or duplications in all patients with a phenotype consistent with 22q deletion or duplication syndromes. In a series of patient specimens with normal karyotypes, no deletions or duplications of the HIRA region were identified.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Ensenauer RE, Adeyinka A, Flynn HC, et al: Microduplication 22q11.2 an emerging syndrome: clinical, cytogenetic and molecular analysis of thirteen patients. Am J Hum Genet 2003;73:1027-1040

2. Yobb TM, Sommerville MJ, Willatt L, et al: Microduplication and triplication of 22q11.2: a highly variable syndrome. Am J Hum Genet 2005;76:865-876

3. Bassett AS, Chow EWC, Husted J, et al: Clinical features of 78 adults with 22q11 deletion syndrome. Am J Med Genet 2005;138A:307-313

4. Manji A, Roberson JR, Wiktor A, et al: Prenatal diagnosis of 22q11.2 deletion when ultrasound examination reveals a heart defect. Genet Med 2001;3:65-66

5. McDonald-McGinn DM, Emanuel BS, Zackai EH: 22q11.2 Deletion Syndrome. GeneReviews, Accessed 05/22/2013, Available at www.ncbi.nlm.nih.gov/books/NBK1523/

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

Identification of 22q deletions and duplications is based on FISH analysis of the critical region locus (HIRA) on the long arm of chromosome 22 (22q11.2). Metaphase cells are examined for the presence of HIRA at 22q11.2 (orange signal) and the control probe arylsulfatase-A (ARSA) at 22q13.3 (green signal). In metaphase cells with a deletion, the abnormal (deleted) chromosome 22 will exhibit only a control probe signal, while signals for both the critical region and control probes will be present on the normal chromosome 22 homolog. Since direct 22q duplications of HIRA may be difficult to detect on metaphase cells, interphase nuclei are scored to identify duplications that would be represented by the observation of 3 orange signals.(Crifasi PA, Michels VV, Discoll DJ, et al: DNA fluorescent probes for diagnosis of velocardiofacial and related syndromes. Mayo Clin Proc 1995;195[70]:1148-1153)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 10 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Amniotic Fl. (remaining supernatant/whole fluid aliquots): Discarded 14 days after report. Blood: 4 weeks. Products of Conception (identifiable fetal tissue): Cremated quarterly after results reported. All Other Specimens: Discarded when results reported.

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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 US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

88271 x 2, 88291-DNA probe, each (first probe set), Interpretation and report

88271 x 2-DNA probe, each; each additional probe set (if appropriate)

88271 x 1-DNA probe, each; coverage for sets containing 3 probes (if appropriate)

88271 x 2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)

88271 x 3-DNA probe, each; coverage for sets containing 5 probes (if appropriate)

88273 w/modifier 52-Chromosomal in situ hybridization, less than 10 cells (if appropriate)

88273-Chromosomal in situ hybridization, 10-30 cells (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)

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
DD22F 22q11.2 Deletion/Duplication, FISH 82246-0
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
51851 Result Summary 50397-9
51853 Interpretation 69965-2
54538 Result 62356-1
CG669 Reason For Referral 42349-1
CG670 Specimen 31208-2
51854 Source 31208-2
51855 Method 85069-3
51852 Additional Information 48767-8
51856 Released By 18771-6
53875 Disclaimer 62364-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports