Test Catalog

Test Id : MAPTZ

MAPT Gene, Sequence Analysis, 7 Exon Screening Panel, Varies

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

Aiding in the diagnosis of frontotemporal dementia, progressive supranuclear palsy, corticobasal degeneration, and dementia with epilepsy

 

Distinguishing the diagnosis of frontotemporal dementia from other dementias, including Alzheimer dementia

 

Identifying individuals who are at risk of frontotemporal dementia

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

Polymerase Chain Reaction (PCR)/DNA Sequencing Analysis

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

MAPT Gene, Sequencing Analysis

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

Frontotemporal dementia

Microtubule-associated protein tau

Pick's disease

Tau

Tauopathy

FTD

MAPTM

Specimen Type
Describes the specimen type validated for testing

Varies

Shipping Instructions

Specimen preferred to arrive within 96 hours of draw.

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

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

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.

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. Molecular Genetics: Neurology Patient Information in Special Instructions

3. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.

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

1 mL

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

All specimens will be evaluated by 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 Ambient (preferred)
Frozen
Refrigerated

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

Aiding in the diagnosis of frontotemporal dementia, progressive supranuclear palsy, corticobasal degeneration, and dementia with epilepsy

 

Distinguishing the diagnosis of frontotemporal dementia from other dementias, including Alzheimer dementia

 

Identifying individuals who are at risk of frontotemporal dementia

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

Frontotemporal dementia is a familial adult-onset, presenile dementia that affects the frontal and temporal cerebral cortices. Clinical presentation is variable and includes changes in behavior, difficulties with language, rigidity, palsy, and saccadic (rapid) eye movement. Symptoms generally begin between 40 and 60 years of age, with mean age of onset at approximately 45 years, and typically last between 5 and 10 years, progressing to severe dementia and mutism. The presentation of frontotemporal dementia may be confused with other dementias, including Alzheimer disease. It is important to distinguish between these different dementias because progression and patient management are different for the various dementias.

 

Based on the immunohistochemical staining, there are 2 main subtypes of frontotemporal lobular degeneration (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.

 

The MAPT gene encodes the microtubule-associated tau protein. A number of mutations have been identified in the MAPT gene that result in aggregation of the tau protein. Although there is variable expression of disease presentation and severity within and between families, the hallmark neurologic lesion constitutes tau-positive protein inclusion bodies. Most clinically significant mutations are found in exons 9 through 13. Several intronic mutations, associated with alternative splicing of the mRNA, contribute to the variability of expression of the disease traits. Mutations in the MAPT gene have also been identified in cases of progressive supranuclear palsy, corticobasal degeneration, and dementia with epilepsy.

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

All detected alterations are evaluated according to American College of Medical Genetics recommendations.(1) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

 

All variants will be reported in reference to transcript NM_001123066 (build GRCh37 (hg19)).

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

Some individuals who are carriers or have a diagnosis of frontotemporal dementia may have a mutation that is not identified by this method (eg, mutations in other exons, promoter mutations). Mutations in other genes have also been implicated in frontotemporal dementia. Abnormalities in other genes are not detected by this assay. The absence of a mutation, therefore, does not eliminate the possibility of positive carrier status or the diagnosis of frontotemporal dementia. For carrier testing, it is important to first document the presence of a MAPT gene mutation in an affected family member.

 

In some cases, DNA alterations of undetermined significance may be identified.

 

Rare polymorphisms exist that could lead to false-negative or false-positive results. If results obtained do not match the clinical findings, additional testing should be considered.

  

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in our interpretation of results may occur if information given is inaccurate or incomplete.

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

1. Richards S, Aziz N, Bale S, et al: Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med 2015 May;17(5):405-424

2. Rademakers R, Cruts M, van Broeckhoven C: The role of tau (MAPT) in frontotemporal dementia and related tau pathies. Hum Mutat 2004 Oct;24(4):277-295

3. Houlden H, Baker M, Adamson J, et al: Frequency of tau mutations in three series of non-Alzheimer's degenerative dementia. Ann Neurol 1999 Aug;46(2):243-248

4. Goedert M: Tau protein and neurodegeneration. Semin Cell Dev Biol 2004 Feb;15(1):45-49

5. Dumanchin C, Camuzat A, Campion D, et al: Segregation of a missense mutation in the microtubule-associated protein tau gene with a familial frontotemporal dementia and parkinsonism. Hum Mol Genet 1998 Oct;7(11):1825-1829

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

Bi-directional sequence analysis is used to test for the presence of a mutation in exons 2, 9, 11, 12, 13, 14, and 15 of the MAPT gene. (Unpublished Mayo method)

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.

Varies

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.

14 to 20 days

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

Whole Blood: 2 weeks (if available) Extracted DNA: 3 months

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, 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 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.

81406-MAPT (microtubule-associated protein tau) (eg, frontotemporal dementia), full gene sequence

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
MAPTZ MAPT Gene, Sequencing Analysis 41092-8
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.
53964 Result Summary 50397-9
53965 Result 82939-0
53966 Interpretation 69047-9
53967 Additional Information 48767-8
53968 Specimen 31208-2
53969 Source 31208-2
53970 Released By 18771-6

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