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Carrier/Mutation-Specific Testing

Carrier/Mutation-Specific Testing

 

For CPT codes, test codes and turn-around times please click here.

 

GeneDx can provide Mutation-Specific Testing for known familial mutations, in any gene, for families that have had previous testing at GeneDx or elsewhere. Mutation-Specific Testing always requires that sufficient information is provided (see links below for details). Mutation-Specific Testing is offered for both symptomatic and asymptomatic individuals, and for dominant, recessive, or maternally inherited mutations. Mutation-Specific Testing is less costly and more rapid than diagnostic analysis of the whole gene. Pricing is dependent on whether testing is done for one or two mutations.

Mutation-specific testing in both parents of a child with recessive mutations is recommended to confirm that all four parental alleles can be detected prior to the testing of other family members. If the child has an apparently homozygous recessive mutation, mutation-specific testing in both parents is strongly recommended to rule out the possibility that the child has one mutated allele and one allele that is deleted or refractory to amplification.

To order this test, please use the Special Services menu located at the top of the second page of the submission form, and please provide information about the mutation in the box on the right side of the page.

For Cardiology mutation-specific testing please click here to fill out the Cardiology Form. 

For Neurology/Mitochondrial mutation-specific testing please click here to fill out the Neurology Form.

Mutation-Specific Testing for Known Familial Mutations: Family Member Previously Tested at GeneDx

  Inheritance Pattern

STEPS when family member was previously tested at GeneDx

Autosomal Dominant

X-Linked

Autosomal Recessive

Maternal

1. Mutation-Specific Testing in both parents of proband prior to testing other family members Recommended Recommended Strongly Recommended* Not Necessary
2. Using the GeneDx Sample Submission Form (Rare Disorders Requisition), select Carrier Detection in Relatives  (#9011-one mutation; 9012-two mutations) from the boxed section on the top of the second page. For mitochondrial DNA (mtDNA) mutations, use the Neurology Test Requisition Form and select #435, #9017 or #9020 from the boxed section at the bottom of the second page. 

  a) Provide the name of the gene 
  b) Provide the name of the mutation 
  c) Provide the GeneDx accession number or the full name of the positive relative that we previously tested.
Required Required Required Required

3. Submit specimen.  Our standard specimens for all tests are a single tube with 1-5 mL blood in EDTA or one pair of GeneDx buccal brushes.  DNA specimens are also accepted.  Please see our standard Specimen Requirements page. Gene deletion/duplication testing requires the submission of blood in EDTA.

Tissue biopsies (muscle or liver) is the preferred specimen for testing mtDNA mutations.

TAT will be 2-3 weeks in most cases** TAT will be 2-3 weeks in most cases** TAT will be 2-3 weeks in most cases** TAT will be 3-4 weeks

 

*Mutation-specific testing in both parents of a child with recessive mutations is recommended to confirm that all four parental alleles can be detected prior to the testing of other family members. If the child has an apparently homozygous recessive mutation, mutation-specific testing in both parents is strongly recommended to rule out the possibility that the child has one mutated allele and one allele that is deleted or refractory to amplification.

**Except for Cardiology/Neurology tests where TAT is 4-5 weeks. 

 

 

 

Family Member Previously Tested at an Outside Laboratory

  Inheritance Pattern

STEPS when family member was tested at an Outside Laboratory

Autosomal Dominant

X-Linked

Autosomal Recessive

Maternal

1. Submit the outside molecular lab results to GeneDx.
To clearly identify the mutation, please provide:

For Nuclear Gene Mutations:

  1. The name of the gene
  2. The mutation in cDNA-level notation (e.g. residue c.123 G to T, where c.1 is the A of the ATG)
  3. One of the following:
    1. The mutation given at the protein level notation (e.g. Gly12Ser or G12S)
    2. The mutation given in g-DNA level notation, with reference to a specific public reference sequence
    3. A DNA sequence at least 30 bases long with the mutated base and mutation indicated

For MtDNA Mutations:

  1. The name of the gene
  2. The position in the mitogenome (m.) using reference sequence NC_012920
Required Required Required Required
2. If the individual to be tested is NOT the proband who was previously tested at the outside laboratory, provide DNA from the proband as a positive  control Strongly Recommended* Strongly Recommended* Strongly Recommended* If ordering Test 9017 or 9020 only
3. Mutation-Specific Testing in both parents of proband prior to testing other family members Recommended Maternal carrier testing recommended Strongly Recommended** Not necessary

4. Using the GeneDx Sample Submission Form (Rare Disorders Requisition), select Carrier Detection in Relatives  (#9011-one mutation; 9012-two mutations) or Confirmation of Mutation Identified elsewhere (#9001-one mutation; 9002-two mutations) from the boxed section on the top of the second page.

For mitochondrial DNA (mtDNA) mutations, use the Neurology Test Requisition Form and select #453, #9017 or #9020 from the boxed section at the bottom of the second page.

Provide the name of the gene and information about the mutation as outlined in Step 1.

Required Required Required Required

5. Submit specimen. Our standard specimens for all sequencing tests are a single tube with 1-5 mL blood in EDTA or one pair of GeneDx buccal brushes.  DNA specimens are also accepted.  Please see our standard Specimen Requirements page.

Tissue biopsies (muscle or liver) is the preferred specimen for testing mtDNA mutations.

Gene deletion/duplication testing requires the submission of blood in EDTA.

TAT will be 2-3 weeks in most cases, unless pos control needs to be tested*** TAT will be 2-3 weeks in most cases, unless pos control needs to be tested***  TAT will be 2-3 weeks in most cases, unless pos control and/or parents need to be tested*** TAT will be 3-4 weeks

 

*DNA from the individual who was previously tested by the outside laboratory is strongly recommended prior to testing additional family members so that GeneDx can ensure that it is able to identify the specific mutation in the family. If a GeneDx report is desired on the previously tested individual, there will be a fee charged (Mutation-Specific Testing CPT codes and pricing). If no report is desired, please label the sample and submission form for this individual with, “POSITIVE CONTROL ONLY-No Report”
If a positive control is not provided, negative results in the Mutation-Specific test will carry a caveat stating that GeneDx did not have the opportunity to confirm that we can detect the mutation in that specific family.

** Mutation-specific testing in both parents of a child with recessive mutations is recommended to confirm that all four parental alleles can be detected prior to the testing of other family members. If the child has an apparently homozygous recessive mutation, mutation-specific testing in both parents is strongly recommended to rule out the possibility that the child has one mutated allele and one allele that is deleted or refractory to amplification. If a GeneDx report is desired on the parents, there will be a fee charged for each parent tested (Mutation-Specific Testing CPT codes and pricing). If no test report is desired for parents, testing is provided free of charge. These samples must be labeled as , “POSITIVE CONTROL ONLY-No Report” on the patient’s submission form.

***Except for Cardiology/Neurology tests where TAT is 4-5 weeks. 

 

 

Information Sheet
Consent Document
 
 
We can analyze any gene to confirm a mutation that has been identified in a research laboratory. Unlike most research laboratories, GeneDx, being a clinical service laboratory, holds CLIA certification and can release results of testing to referring physicians for use in diagnosis, counseling, and development of a treatment plan.
 

What is the process?

Testing through GeneDx must be ordered by a physician, genetic counselor or other health care professional. A new sample (either blood or buccal brushes) from the individual is required to determine if the mutation is present. Confirmation of the mutation in a previously tested individual is necessary before we can perform carrier testing or prenatal diagnosis in a family. Please Note: Prenatal testing is not available for mtDNA mutations.

If the research lab has not completed analysis of the implicated gene or if they have not identified a mutation after performing the screening tests, GeneDx may be able, in some cases, to develop a new test to sequence the gene or genes known to be associated with the diagnosis. If there is a gene for which you would like to see testing made available, please let us know.

What information is required when ordering a mutation confirmation test?

Mutation information should be provided to GeneDx in advance, in the form of a publication, lab report, or other communication from the laboratory in which the mutation was previously observed. To clearly identify the mutation, please provide:

For Nuclear Gene Mutations:

  1. The name of the gene 

  2. The mutation in cDNA-level notation (e.g. residue c.123 G to T, where c.1 is the A of the initiator ATG)

  3. One of the following:
    1. The mutation given in protein-level notation (e.g. Gly12Ser or G12S)
    2. The mutation given in gDNA-level notation, with reference to a specific public reference sequence
    3. A DNA sequence at least 30 bases long with the mutated base and mutation indicated 

For MtDNA Mutations:

  1. The name of the gene
  2. The position in the mitogenome (m.) using reference sequence NC_012920

How is Mutation Confirmation ordered?

Using the GeneDx Sample Submission Form (Rare Disorders Requisition), select “Confirmation of mutation identified elsewhere” in the boxed section of the test list on page 2. Provide the name of the gene and name of the mutation. Also enclose a copy of the research report, if available. For mitochondrial DNA (mtDNA) mutations, use the Neurology Test Requisition Form and select #453, #9017 or #9020 from the boxed section at the bottom of the second page.

What is the turn-around time?

Results of mutation confirmations are generally available in 3-4 weeks. A written report is faxed to the referring health professional.

(We will occasionally consider doing complete sequence analysis of a gene that is not in our current menu of tests. Please contact GeneDx directly).

 

 

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