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Test ID: CAT22    
22q11.2 Deletion/Duplication, FISH

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)

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

Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

2-7 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

10 days

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

Indefinitely

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

Rochester