Test ID: GRNKM
Progranulin Gene (GRN), Known Mutation
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Screening of at-risk individuals when a mutation in the GRN gene has been identified in an affected family member
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
Documentation of the specific familial mutation must be provided
with the specimen in order to perform this test.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Polymerase Chain Reaction (PCR)/DNA Sequencing Analysis
(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
Aliases Lists additional common names for a test, as an aid in searching
Frontotemporal Dementia (FTD)
Frontotemporal Lobar Degeneration (FLTD)
FTD (Frontotemporal Dementia)
PGRN (Progranulin)
Progranulin (PGRN)
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.
This test can only be performed if a mutation has previously been identified in an affected family member of this individual.
Specimen must arrive within 96 hours of draw.
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
Forms:
1. 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.
2. Molecular Genetics-Congenital Inherited Diseases Patient Information Sheet (Supply T521) in Specimen Instructions
3. If not ordering electronically, submit a Molecular Genetics Request Form (Supply T245) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Frozen | ||
| Refrigerated | ||
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Frontotemporal lobar degeneration (FTLD) describes a group of neurodegenerative diseases that are frequent causes of dementia, accounting for 5% to 10% of all dementia patients and 10% to 20% of patients with onset of dementia before age 65. Frontotemporal dementia (FTD) is the most common clinical manifestation of FTLD. The clinical presentation of FTD is variable, but typically includes changes in personality and social conduct, often associated with disinhibition, followed by more general cognitive decline, eventually leading to dementia. The age of onset is extremely variable, ranging from 35 to 87 years. Duration of the disease ranges from 3 to 12 years.
Based on the immunohistochemical staining, there are 2 main subtypes of FTLD: tau-positive FTLD and tau-negative FTLD with ubiquitin-positive inclusions (FTLD-U). Mutations in the MAPT gene have been identified in patients with tau-positive FTLD; mutations in the progranulin gene (GRN) have been identified in patients with FTLD-U. Both MAPT and GRN are located on chromosome 17q21, with GRN located only 1.7 Mb centromeric of MAPT. GRN consists of 12 coding exons and 1 noncoding exon.
GRN encodes progranulin, a multifunctional protein that plays a role in multiple processes including development, wound repair, and inflammation. The function of GRN in the brain is not well understood, but progranulin is widely expressed in neurons and glial cells. More than 40 different pathogenic GRN mutations have been reported. All pathogenic mutations identified to date create functional null alleles that result in decreased progranulin production, suggesting that reduced levels of progranulin may lead to neurodegeneration.
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
The identification of a disease-causing mutation in an affected family member is necessary before predictive testing for other family members can be offered. If a familial mutation has not been previously identified, order #89188 Progranulin Gene (GRN), Full Gene Analysis.
Analysis is performed for the familial mutation(s) provided only. This assay does not rule out the presence of other mutations within this gene or within other genes that may be associated with frontotemporal dementia.
We strongly recommend that patients undergoing predictive testing receive genetic counseling both prior to testing and after results are available.
Predictive testing of an asymptomatic child is not recommended.
Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Any error in the diagnosis or in the pedigree provided to us, including false-paternity, could lead to erroneous interpretation of results.
A previous bone marrow transplant from an allogenic donor will interfere with testing. Call Mayo Medical Laboratories for instructions for testing patients who have received a bone marrow transplant.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Rademakers R, Hutton M: The genetics of frontotemporal lobar degeneration. Curr Neurol Neurosci Rep 2007 Sep;7(5):434-42
2. Gass J, Cannon A, Mackenzie IR, Boeve B, et al: Mutations in progranulin are a major cause of ubiquitin-positive frontotemporal lobar degeneration. Hum Molec Genet 2006 Oct 15;15(20):2988-3001
3. Cruts M, Gijselinck I, van der Zee J, et al: Null mutations in progranulin cause ubiquitin-positive frontotemporal dementia linked to chromosome 17q21. Nature 2006 Aug 24, 442(7105):920-924
4. Eriksen JL, Mackenzie IR: Progranulin: normal function and role in neurodegeneration. J Neurochem 2008;104:287-297
Method Description Describes how the test is performed and provides a method-specific reference
DNA sequencing is utilized to test for the presence of a mutation in the GRN gene that was previously identified in a family member. (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; 10 a.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
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.
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 |
|---|---|---|
| 29662 | Specimen | 31208-2 |
| 29663 | Specimen ID | N/A |
| 29664 | Source | N/A |
| 29665 | Order Date | N/A |
| 29666 | Reason For Referral | 42349-1 |
| 29667 | Method | In Process |
| 29668 | Result | In Process |
| 29669 | Interpretation | 69047-9 |
| 29851 | Extraction Performed? | N/A |
| 29670 | Amendment | In Process |
| 29671 | Reviewed By: | N/A |
| 29672 | Release Date | N/A |
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