FOXL2 Mutation (C402G) Analysis by PCR and Pyrosequencing
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
An aid in the diagnosis of adult granulosa cell tumor
Additional Tests Lists test(s) that are always performed, at an additional charge, with the initial test(s)
|Test ID||Reporting Name||Available Separately||Always Performed|
|60254||AP Special Studies Review||No||Yes|
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
This test is performed in conjunction with 60254 AP Special Studies Review and 70011 Slide Review. Additional testing may be performed after review by pathologist. Upon approval from the requesting clinician, 60254 AP Special Studies Review could be changed to 70012 Pathology Consultation, if determined to be more appropriate.
Polymerase Chain Reaction (PCR) and Pyrosequencing
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
FOXL2 Mutation (C402G) Analysis
Granulosa cell tumor
Granulosa cell tumor
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
A pathology/diagnostic report including a brief history is required.
Container/Tube: Surgical Pathology Packaging Kit (Supply T554) requested, but not required
Preferred: Formalin-fixed, paraffin-embedded (FFPE) tissue block with a minimum of 40% tumor cell population
Acceptable: Unstained slides with a minimum of 40% tumor population; slides may be stained and/or scraped
1. Process all fresh or frozen specimens into FFPE blocks prior to submission.
2. If submitting slides, a minimum of five, 4- to 5-micron thick, unstained slides are required.
1. A quality specimen is essential for evaluation. Submit only tissue containing tumor cells; minimal tissue is required for evaluation.
2. Special stains performed outside Mayo Medical Laboratories and included with the case may be repeated and charged at the reviewing pathologist's discretion. Testing requested by referring physician may not be performed if deemed unnecessary by Mayo Clinic pathologist.
Forms: If not ordering electronically, submit a Pathology/Cytology Request Form (Supply T246) with the specimen.
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Granulosa cell tumor (GCT) represents approximately 5% to 10% of all ovarian malignancies and is the most common type of malignant ovarian sex-cord stromal tumor. The majority of patients with GCT (95%) are adults and 5% are juveniles. The histopathological diagnosis of GCT is challenging. Forkhead box L2 (FOXL2) gene is involved in ovarian development and function. The FOXL2 gene point mutation 402C>G in exon 1 (C134W) was reported in the majority of adult GCT (>90%), 5% to 10% of thecomas (tumors closely related to GCT) and <10% of juvenile GCT cases, but not in other ovarian tumors. Detection of FOXL2 mutation aids in the clinical diagnosis of adult GCT.
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.
The presence of Forkhead box L2 (FOXL2) mutation 402C>G supports the diagnosis of granulosa cell tumor (GCT), but does not rule out the diagnosis of ovarian thecomas (5%-10%). The presence of wild-type FOXL2 does not rule-out the diagnosis of GCT.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Reliable results are dependent on adequate specimen collection and processing. This test has been validated on formalin-fixed, paraffin-embedded tissues; other types of fixatives are discouraged. Improper treatment of tissues, such as decalcification, may cause PCR failure. False-negative results may occur in heterozygous tumor specimens when tumor cells comprise <40% of the cell population. Tumor cells are routinely enriched by macrodissection to avoid false-negative results.
Clinical diagnosis or therapy should not be based solely on this assay. The results should be considered in conjunction with clinical information, histologic evaluation, and additional diagnostic tests.
The Forkhead box L2 (FOXL2) mutation was tested by PCR and pyrosequencing in 102 formalin-fixed, paraffin-embedded (FFPE) tissues, including 53 granulosa cell tumors (GCT) and 49 other non-GCT tissues. Using pathological diagnoses as references, the FOXL2 mutation pyrosequencing test demonstrated the following characteristics: clinical sensitivity (66%), clinical specificity (93.9%), positive predict value (92.1%), and negative predict value (71.9%). The clinical sensitivity was significantly different in GCT subtypes: regular GCT (87%), GCT-diffuse type (66.6%), and GCT with prominent fibrothecomatous component (33.3%). The pyrosequencing results were confirmed by conventional PCR and direct sequencing in all cases.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Shah SP, Kobel M, Senz J, et al: Mutation of FOXL2 in granulosa-cell tumors of the ovary. N Engl J Med 2009;360:2719-2729
2. Kim MS, Hur SY, Yoo NJ, et al: Mutational analysis of FOXL2 codon 134 in granulosa cell tumour of ovary and other human cancers. J Pathol 2010;221:147-152
3. Schrader KA, Gorbatcheva B, Senz J, et al: The specificity of the FOXL2 c.402C->G somatic mutation: a survey of solid tumors. PLoS One 2009 Nov 24;4(11):e7988
4. Benayoun BA, Kalfa N, Sultan C, et al: The forkhead factor FOXL2: a novel tumor suppressor? Biochim Biophys Acta 2010;1805:1-5
Method Description Describes how the test is performed and provides a method-specific reference
The paraffin-embedded tissue is deparaffinized, lysed, and digested. Genomic DNA is extracted from patient ovarian specimens using either a phenol-chloroform method or the QIAamp DNA FFPE Tissue kit (Qiagen). Forkhead box L2 (FOXL2) gene exon 1 is amplified using specific primers by PCR. Controls are run with each specimen to assess possible contamination issues and overall test performance. The PCR products from patient specimen and negative controls are used for pyrosequencing. The pyrograms are analyzed and the presence or absence of the FOXL2 mutation (402C>G) is determined. The results are interpreted by a working group pathologist.(Qiagen DNA FFPE Tissue Handbook, Qiagen PyroMark Gold Q24 reagents Handbook; unpublished Mayo method)
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.
Monday through Friday; 8 a.m.-5 p.m.
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.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
1 week/7 days
Performing Laboratory Location The location of the laboratory that performs the test
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's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test was developed and its performance characteristics 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 Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
81479-Unlisted molecular pathology procedure
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|60694||FOXL2 Mutation (C402G) Analysis||N/A|