Test Catalog

Test ID: FMTT    
Familial Mutation, Targeted Testing, Varies

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

Diagnostic or predictive testing for specific conditions when 1 or more variants have been identified in a family member

                   

Carrier screening for individuals at risk for having a variant that was previously identified in a family member

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request

Documentation of the specific familial variants is required and must be provided with the specimen in order to perform this test. Consultation with the laboratory is required prior to ordering this test.

 

Note: analysis of the area surrounding the familial variant may be required in the performance of this assay, which could result in identification of additional variants. Contact the laboratory at 800-533-1710 with any questions regarding assay performance.

 

The preferred specimen for this test is whole blood. Other specimens may be acceptable for certain genes as follows.

 

The following genes are available for testing on the blood spot specimen type:

ABCD1, ACADM, ACADS, ACADVL, ARSA, ARSB, CFTR*, CPT2, CPOX, FECH, FTCD, GAA, GALT, GALC, GBA, GLA, GNS, HMBS, IDS, IDUA, MMACHC, MMADHC, NAGLU, PPOX, SGSH, SLC25A20, SMN1, SMPD1, and SUMF1

*Note: CFTR deletion/duplication analysis is not offered on dried blood spot specimens.

 

The following genes are available for testing on fibroblasts and skin biopsy specimen types:

ABCD1, ACADM, ACADS, ACADVL, APOA1, APOA2, ARSA, ARSB, ATP7B, BTD, CDKN1C, CPOX, CPT2, CTRC, FECH, FGA, FTCD, GAA, GALC, GALT, GBA, GLA, GNPTAB, GNS, GRN, GSN, HEXA, HMBS, IDS, IDUA, LYZ, MAPT, MMACHC, MMADHC, NAGLU, PKHD1, PPOX, PRSS1, RET, SCG5, SGSH, SLC25A20, SMN1, SMPD1, SPINK1, SUMF1, TTR, and UBE3A

 

Due to the complexity of prenatal testing, consultation with the laboratory is required for all prenatal testing.

 

The following genes are available for testing on prenatal specimen types:

ABCD1, AGXT, ARSA, ARSB, BTD, CDKN1C, CFTR, CPT2, GLA, GALC, GALT, GBA, GNPTAB, GNS, GRHPR, HEXA, IDS, IDUA, MLYCD, MMACHC, MMADHC, NAGLU, NPC1, NPC2, PKHD1, SGSH, SLC25A20, SMN1, SMPD1, SUMF1, and UBE3A. Contact the laboratory to inquire about genes not included on this list.

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

For prenatal specimens only: If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture will be added and charged separately. If chorionic villus specimen (nonconfluent cultured cells) is received, fibroblast culture will be added and charged separately. For any prenatal specimen that is received, maternal cell contamination studies will be added.

 

Testing for variants detected by whole exome sequencing (WES) or large panels: Any familial mutation targeted testing (FMTT) orders for a variant that was detected by WES or next-generation sequencing (NGS) large panel assays requires a proband sample that has been previously tested at Mayo Clinic Laboratories. Contact the laboratory to determine whether adequate DNA is available in the laboratory or if a new proband sample is required.

 

The following algorithms are available in Special Instructions:

-Full Gene Analysis/Multi-Gen Panels versus Familial Mutation Targeted Testing

-Lynch Syndrome Testing Algorithm

-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm

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

This test is available to test for the presence of 1 or more variants previously identified in a family member. Targeted testing is used for diagnostic or predictive testing in cases in which variants have been previously identified in an affected family member. Targeted testing is available for the genes listed in the table below or variants in genes detected previously by large panels or whole exome sequencing (WES) at Mayo Clinic Laboratories.

 

Genes Available for Testing*

ABCD1

ACADM

ACADS

ACADVL

AGXT

APC

APOA1

APOA2

ARSA

ARSB

ATP7B

AXIN2

BMPR1A

BRCA1

BRCA2

BTD

CASR

CDH1

CDKN1C

CFTR

CHEK2

CPOX

CPT2

CTRC

DMD

FECH

FGA

FLCN

FTCD

G6PD

GAA

GALC

GALT

GBA

GJB2

GLA

GNPTAB

GNS

GRHPR

GRN

GSN

HEXA

HBA1/HBA2

HBB

HGSNAT

HMBS

IDS

IDUA

LYZ

MAPT

MAX

MECP2

MLH1

MLH3

MLYCD

MMACHC

MMADHC

MSH2

MSH6

MUTYH

NAGLU

NPC1

NPC2

PKHD1

PMS2

PMP22

PPOX

PRSS1

PSAP

PTEN

RAI1

RET

SERPINA1

SCG5

SDHAF2

SDHB

SDHC

SDHD

SEPT9

SGSH

SLC25A20

SMAD4

SMN1

SMPD1

SPINK1

STK11

SUMF1

TACSTD1/EPCAM

THEM127

TP53

TTR

UBE3A

VHL

 

 

 

 

*FMTT is available for family members of a patient who had testing performed by the Genomics Laboratory at Mayo Clinic Laboratories. For these individuals, this test can be used to detect variants in the genes listed in the table above, in addition to any gene detected via large panels or WES. Contact the laboratory to determine whether adequate DNA is available in the laboratory or if a new proband sample is required.

 

Refer to the following resources for information regarding the listed gene targets. GeneReviews-NCBI Bookshelf, available at www.ncbi.nlm.nih.gov/books/NBK1116/ or OMIM, available at www.omim.org/.

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 and Genomics (ACMG) recommendations.(1) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

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

Clinical Correlations:

The identification of a disease-causing variant in an affected family member is necessary before predictive testing for other family members can be performed. If a familial variant has not been previously identified, call 800-533-1710 to discuss testing options.

 

Test results should be interpreted in the context of clinical findings, family history, and other laboratory testing. Misinterpretation of results may occur if the information provided is inaccurate or incomplete.

 

Technical Limitations:

Rare allelic variants (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.

 

Analysis is performed for the familial variants provided only. This assay does not rule out the presence of other variants within this gene or within other genes that may be associated with hereditary cancer syndromes.

Note: Analysis of the area surrounding the familial variant may be required in the performance of this assay, which could result in identification of additional variants. Contact the laboratory with any questions regarding assay performance.

 

In addition to disease-related probes, the multiplex ligation-dependent probe amplification technique utilizes probes localized to other chromosomal regions as internal controls. In certain circumstances, these control probes may detect other diseases or conditions for which this test was not specifically intended. Results of the control probes are not normally reported. However, in cases where clinically relevant information is identified, the ordering physician will be informed of the result and provided with recommendations for any appropriate follow-up testing.

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

Special Instructions Library of PDFs including pertinent information and forms related to the test