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Test Code MISC2MAYOFMTT Familial Mutation, Targeted Testing, Varies

Useful For

Diagnostic or predictive testing for specific conditions when a DNA variant of interest has been previously identified in a family member and follow-up testing for this specific variant in other family members is desired


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


Segregation analysis for a familial DNA variant


Confirmation of germline status for variants detected via somatic testing

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
CRYOB Cryopreserve for Biochem Studies No No
FIBR Fibroblast Culture Yes No

Testing Algorithm

For prenatal specimens only: If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture/genetic test will be added at an additional charge. If chorionic villus specimen (nonconfluent cultured cells) is received, fibroblast culture for genetic test will be added at an additional charge.


For any prenatal specimen that is received, maternal cell contamination studies will be added.


If skin biopsy is received, fibroblast culture and cryopreservation for biochemical studies will be performed at an additional charge. If viable cells are not obtained, the client will be notified.


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

Method Name

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

Reporting Name

Familial Mutation, Targeted Testing

Specimen Type


Ordering Guidance

This test can only be performed if a variant was previously detected in a family member of this individual. Please contact the laboratory for further information regarding requests for germline confirmation of somatic results or clinical confirmation of research results.

Additional Testing Requirements

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


If the familial variant was previously identified at an outside laboratory, sending a proband sample (ie, blood or DNA from a family member with a positive genetic test result) to be used as a positive control is strongly recommended to ensure that the specific familial variant can be detected by our laboratory. Proband samples should be sent as a separate FMTT order, under the proband's identifiers (ie, do not send the patient and proband samples under the same order). If a positive control is not provided, the possibility of a false negative result should be considered.

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.

Necessary Information

The identification of a specific variant in an affected family member is required before this test can be performed for additional family members. If a familial variant has not been previously identified, call 800-533-1710 to discuss testing options.


Familial Mutation Testing: Required Patient Information form (T721) with documentation of the specific familial variant(s) is required. Testing will be held until information is received. If information is not received within 14 days of sample receipt, testing may be canceled.

Specimen Required

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.


Submit only 1 of the following specimen types:



Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated 14 days


Specimen Type: Blood spot

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


Preferred: Collection card (Whatman Protein Saver 903 Paper)

Acceptable: Whatman FTA Classic paper, PerkinElmer 226 (formerly Ahlstrom 226) filter paper, or 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 or older is a fingerstick. For infants younger than 1 year, a heel stick should be used. See Dried Blood Spot Collection Tutorial for how to collect blood spots via fingerstick.

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

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

4. Do not stack wet specimens.

5. Keep specimen dry.

Specimen Stability Information: Ambient (preferred)/Refrigerated

Additional Information:

1. For collection instructions, see Blood Spot Collection Instructions

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

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


Specimen Type: Cultured fibroblasts

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

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

Additional Information: Indicate the tests to be performed on the fibroblast culture cells. A separate culture charge will be assessed under FIBR / Fibroblast Culture, Tissue. An additional 4 weeks is required to culture fibroblasts before genetic testing can occur.

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


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.

Specimen Volume: 4-mm punch

Specimen Stability Information: Refrigerated (preferred)/Ambient

Additional Information: A separate culture charge will be assessed under FIBR / Fibroblast Culture, Tissue. An additional 4 weeks is required to culture fibroblasts before genetic testing can occur.


Specimen Type: Cord blood

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions:

1. Send specimen in original tube

2. Label specimen as cord blood

Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated 14 days


Specimen Type: Extracted DNA

Container/Tube: 2 mL screw top tube

Specimen Volume: 100 mcL (microliters)

Collection Instructions:

1. The preferred volume is 100 mcL at a concentration of 250 ng/mcL.

2. Include concentration and volume on tube.

Specimen Stability Information: Frozen (preferred)/Ambient/Refrigerated


Prenatal Specimens

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


Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 mL

Specimen Stability Information: Refrigerated (preferred)/Ambient

Additional Information: A separate culture charge will be assessed under CULAF / Culture for Genetic Testing, Amniotic Fluid.


Specimen Type: Cultured amniocytes

Container/Tube: T-25 flask

Specimen Volume: 2 Full flasks

Collection Instructions: Submit confluent cultured cells from another laboratory.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Specimen Type: Chorionic villi

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

Specimen Volume: 20 mg

Specimen Stability Information: Refrigerated

Additional Information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Genetic Testing, Tissue.


Specimen Type: Cultured chorionic villi

Container/Tube: T-25 flasks

Specimen Volume: 2 Full 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: 10 mg
Blood Spots: 2

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

This test is available for the analysis of up to 4 genetic variants (single nucleotide variant, small insertion/deletion, or exon level deletion/duplication).Targeted testing is used for diagnostic or predictive testing in family members of an affected individual with a previously detected variant, carrier screening, segregation analysis, confirmation of research results, or testing for germline status of a variant detected by somatic or tumor testing. This test is available for any of the genes on Mayo Clinic Laboratories' (MCL) test menu. In addition, genes not on the MCL test menu may be able to be tested. Call the laboratory at 800-533-1710 with specific inquiries.

Reference Values

An interpretive report will be provided.


Evaluation and categorization of variants is performed using 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.

Method Description

DNA sequencing and/or dosage analysis by, quantitative polymerase chain reaction, array comparative genomic hybridization, or multiplex ligation-dependent probe amplification is utilized to test for the presence of the specific variants previously identified in a family member or via alternate testing (research, somatic).(Unpublished Mayo method)

Day(s) Performed

Monday through Friday

Report Available

15 to 22 days

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 US 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 85069-3
36535 Released By 18771-6


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:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Familial Mutation Testing: Required Patient Information (T721)

3. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Hematopathology/Cytogenetics Test Request

-Cardiovascular Test Request (T724)

Secondary ID


CPT Code Information


CPT Code
(as appropriate)

Any gene not listed below













































81265-Maternal cell contamination (if appropriate)

88233-Tissue culture, skin or solid tissue biopsy (if appropriate)

88235-Tissue culture for amniotic fluid (if appropriate)

88240-Cryopreservation (if appropriate)