Test Catalog

Test ID: MISCF    
Miscellaneous Studies Using Chromosome-Specific Probes, FISH

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

Resolution of unusual or complex structural alterations, questionable mosaicism, and unbalanced chromosome abnormalities that cannot be resolved by chromosome or chromosomal microarray analysis


Identifying gain, loss, or rearrangement of chromosome regions using gene or locus-specific probes

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

Consult with the laboratory before ordering this test.


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 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

Conventional cytogenetic studies can identify the presence of chromosome abnormalities and most mosaic conditions. In approximately 2% of these chromosomally abnormal cases, the genetic makeup of the chromosome abnormality can be identified, but not completely characterized, by conventional techniques alone. For malignant disorders, the proportion of specimens with unresolvable chromosome abnormalities is much higher. Chromosomal microarray analysis (CMA) can detect copy number gain or loss of a chromosomal region but cannot identify the mechanism.


FISH using gene-specific probes and various probe strategies can help characterize chromosome abnormalities. This includes abnormalities that cannot be accurately characterized by chromosome analysis or CMA such as unusual structural alterations, and unbalanced chromosome abnormalities such as deletions, duplications, and translocations. Scoring large numbers of interphase nuclei can more accurately establish the frequency of chromosome abnormalities and assess level of mosaicism.

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

An interpretive report will be provided.

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

This test should not be ordered without prior consultation and approval by the laboratory.


This test is not approved by the U.S. Food and Drug Administration and it is best used as an adjunct to existing clinical and pathologic information.

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

1. Remstein ED, Dogan A, Einerson RR, et al: The incidence and anatomic site specificity of chromosomal translocations in primary extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in North America. Am J Surg Pathol 2006 Dec;30(12):1546

2. Fonseca R, Blood E, Rue M, et al: Clinical and biologic implications of recurrent genomic aberrations in myeloma. Blood 2003 Jun 1;101(11):4569-4575

3. Van Dyke DL, Shanafelt TD, Call TG, et al: A comprehensive evaluation of the prognostic significance of 13q deletions in patients with B-chronic lymphocytic leukaemia. Br J Haematol 2010;148:544-550

4. Wiktor A, Van Dyke DL: FISH analysis helps identify low-level mosaicism in Ullrich-Turner syndrome patients. Genet Med 2004;6:132-135