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Test ID FMTT Familial Mutation, Targeted Testing, Varies

Useful For

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

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:


*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:



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.

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
MATCC Maternal Cell Contamination, B Yes No
CULFB Fibroblast Culture for Genetic Test Yes No
CULAF Amniotic Fluid Culture/Genetic Test Yes No
_G001 Gene GRHPR No, (Bill Only) No
_G002 Gene PPOX No, (Bill Only) No
_G003 Gene CFTR_SEQ No, (Bill Only) No
_G004 Gene CFTR_MLPA No, (Bill Only) No
_G005 Gene MLH1 No, (Bill Only) No
_G006 Gene MSH2 No, (Bill Only) No
_G007 Gene MSH6 No, (Bill Only) No
_G008 Gene MECP2_SEQ No, (Bill Only) No
_G009 Gene MLH3 No, (Bill Only) No
_G010 Gene CHEK2 No, (Bill Only) No
_G011 Gene IDUA No, (Bill Only) No
_G012 Gene AXIN2 No, (Bill Only) No
_G013 Gene BMPR1A No, (Bill Only) No
_G014 Gene PTEN No, (Bill Only) No
_G015 Gene SMAD4 No, (Bill Only) No
_G016 Gene STK11 No, (Bill Only) No
_G017 Gene TP53 No, (Bill Only) No
_G018 Gene IDS No, (Bill Only) No
_G019 Gene FLCN No, (Bill Only) No
_G020 Gene SPINK1 No, (Bill Only) No
_G021 Gene PRSS1 No, (Bill Only) No
_G022 Gene CTRC No, (Bill Only) No
_G025 Gene ABCD1 No, (Bill Only) No
_G026 Gene CDH1 No, (Bill Only) No
_G027 Gene NAGLU No, (Bill Only) No
_G028 Gene SGSH No, (Bill Only) No
_G029 Gene ARSB No, (Bill Only) No
_G030 Gene GNPTAB No, (Bill Only) No
_G031 Gene SEPT9 No, (Bill Only) No
_G032 Gene ACADVL No, (Bill Only) No
_G033 Gene ACADM No, (Bill Only) No
_G034 Gene ACADS No, (Bill Only) No
_G035 Gene FECH No, (Bill Only) No
_G036 Gene MAPT No, (Bill Only) No
_G037 Gene PKHD1 No, (Bill Only) No
_G038 Gene GRN No, (Bill Only) No
_G039 Gene FTCD No, (Bill Only) No
_G040 Gene CDKN1C No, (Bill Only) No
_G041 Gene CPOX No, (Bill Only) No
_G042 Gene ATP7B No, (Bill Only) No
_G043 Gene GAA No, (Bill Only) No
_G044 Gene HMBS No, (Bill Only) No
_G045 Gene GALT No, (Bill Only) No
_G046 Gene GLA No, (Bill Only) No
_G047 Gene BTD No, (Bill Only) No
_G048 Gene HEXA No, (Bill Only) No
_G049 Gene AGXT No, (Bill Only) No
_G050 Gene APC No, (Bill Only) No
_G051 Gene MLYCD No, (Bill Only) No
_G052 Gene MMACHC No, (Bill Only) No
_G053 Gene GBA No, (Bill Only) No
_G054 Gene SMPD1 No, (Bill Only) No
_G055 Gene CPT2 No, (Bill Only) No
_G056 Gene TTR No, (Bill Only) No
_G057 Gene UBE3A No, (Bill Only) No
_G058 Gene GALC No, (Bill Only) No
_G059 Gene GSN No, (Bill Only) No
_G060 Gene LYZ No, (Bill Only) No
_G061 Gene FGA No, (Bill Only) No
_G062 Gene APOA1 No, (Bill Only) No
_G063 Gene APOA2 No, (Bill Only) No
_G064 Gene MMADHC No, (Bill Only) No
_G065 Gene SLC25A20 No, (Bill Only) No
_G066 Gene ARSA No, (Bill Only) No
_G067 Gene NPC1/2_SEQ and NPC1/2_MLPA No, (Bill Only) No
_G068 Gene PMS2_LR and PMS2_SEQ No, (Bill Only) No
_G069 Gene PMS2_MLPA No, (Bill Only) No
_G070 Gene RAI1 No, (Bill Only) No
_G071 Gene MUTYH No, (Bill Only) No
_G072 Gene HGSNAT No, (Bill Only) No
_G073 Gene GNS and GRHPR_MLPA No, (Bill Only) No
_G074 Gene PSAP No, (Bill Only) No
_G075 Single-gene Large Del/Dup No, (Bill Only) No
_G076 Gene MECP2_MLPA No, (Bill Only) No
_G077 Gene RET No, (Bill Only) No
_G078 Gene SUMF1 No, (Bill Only) No
_G079 Gene CASR_Seq No, (Bill Only) No
_G080 Gene VHL_SEQ No, (Bill Only) No
_G081 VHL_MLPA No, (Bill Only) No
_G082 Gene SHDP_MLPA No, (Bill Only) No
_G083 Gene SDHB, SDHC, and SDHD_MLPA No, (Bill Only) No
_G084 Gene SDHB, SDHC, SDHD_Seq No, (Bill Only) No
_G085 Gene BRCA1 No, (Bill Only) No
_G086 Gene BRCA2 No, (Bill Only) No
_G087 Gene DMD_MLPA No, (Bill Only) No
_G088 Gene PMP22_MLPA No, (Bill Only) No
_G089 Gene MPZ_MLPA No, (Bill Only) No
_G102 Gene SERPINA1 No, (Bill Only) No
_G112 Gene SDHAF2 No, (Bill Only) No
_G113 Gene TMEM127 No, (Bill Only) No
_G114 Gene MAX No, (Bill Only) No
_G115 Gene SMN1 No, (Bill Only) No
_G125 Gene PMP22_SEQ No, (Bill Only) No
_G127 Gene GJB2_SEQ No, (Bill Only) No
_G128 Gene HBA1/HBA2_SEQ No, (Bill Only) No
_G129 Gene HBB_SEQ No, (Bill Only) No
_G130 Known Familial Variant,Other No, (Bill Only) No
G168 Gene CSTB No, (Bill Only) No
G169 Gene CACNA1A No, (Bill Only) No

Testing Algorithm

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:

-Fabry Disease Diagnostic Testing Algorithm

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

-Lynch Syndrome Testing Algorithm

-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm

Method Name

Polymerase Chain Reaction (PCR) followed by DNA Sequencing Analysis, Gene Dosage Analysis by Array Comparative Genomic Hybridization (aCGH), and/or Gene Dosage Analysis by Multiplex Ligation-Dependent Probe Amplification (MLPA)

Reporting Name

Familial Mutation, Targeted Testing

Specimen Type


Advisory Information

This test can only be performed if a variant has previously been identified in a family member of this individual.

Additional Testing Requirements

All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.


Prenatal specimens can be sent Monday through Thursday and must be received by 5 p.m. CST on Friday in order to be processed appropriately.

Necessary Information

Testing may be delayed if the required documentation is not received (ie, Familial Mutation Testing: Required Patient Information [T721]) in Special Instructions.

Specimen Required

Refer to Genetics Information for a complete list of genes tested by specimen type.


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


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.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Specimen Type: Cultured fibroblasts

Container/Tube: T-75 or T-25 flask

Specimen Volume: 1 Full T-75 or 2 full T-25 flasks

Specimen Stability Information: Ambient (preferred)/Refrigerated <24 hours


Specimen Type: Blood spot

Supplies: Card-Blood Spot Collection (Filter Paper) (T493)

Preferred: Collection card (Whatman Protein Saver 903 Paper)

Acceptable: Ahlstrom 226 filter paper, or Card-Blood Spot Collection Card

Specimen Volume: 2 to 5 Blood spots on collection card

Collection Instructions:

1. An alternative blood collection option for a patient >1 year of age is finger stick.

2. Let blood dry on the filter paper at ambient temperature in a horizontal position for 3 hours.

3. Do not expose specimen to heat or direct sunlight.

4. Do not stack wet specimens.

5. Keep specimen dry

Additional Information:

1. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777) in Special Instructions.

2. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800) in Special Instructions.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Specimen Type: Tissue

Container/Tube: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block.


Specimen Type: Skin biopsy

Supplies: Fibroblast Biopsy Transport Media (T115)

Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin. Tubes can be supplied upon request (Eagle's minimum essential medium with 1% penicillin and streptomycin).

Specimen Volume: 4-mm punch

Specimen Stability Information: Refrigerated (preferred)/Ambient


Prenatal Specimens


Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 mL

Specimen Stability Information: Refrigerated (preferred)/Ambient


Specimen Type: Chorionic villi

Container/Tube: 15-mL tube containing 15 mL of transport media

Specimen Volume: 20 mg

Specimen Stability Information: Refrigerated



Specimen Type: Confluent cultured cells

Container/Tube: T-25 flask

Specimen Volume: 2 Flasks

Collection Instructions: Submit confluent cultured cells from another laboratory.

Specimen Stability Information: Ambient (preferred)/Refrigerated

Specimen Minimum Volume

Amniotic Fluid: 10 mL
Blood: 1 mL
Chorionic Villi: 5 mg
Blood Spots: 2

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; Varies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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.

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FMTT Familial Mutation, Targeted Testing 51966-0


Result ID Test Result Name Result LOINC Value
36528 Result Summary 50397-9
36529 Result 82939-0
36530 Interpretation 69047-9
36531 Additional Information 48767-8
36532 Specimen 31208-2
36533 Source 31208-2
36534 Method 49549-9
36535 Released By 18771-6

NY State Approved



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. Familial Mutation Testing: Required Patient Information (T721) in Special Instructions

3. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.