Previously Tested at Research Facility

Info Sheet

We can analyze almost any gene to confirm a variant that has been identified in a research laboratory. Unlike most research laboratories, GeneDx is a CLIA-certified clinical service laboratory and can release results of testing to referring physicians for use in diagnosis, counseling, and development of a treatment plan.


  • Must be ordered by a physician, genetic counselor or other health care professional.
  • A new sample (usually blood or buccal swab) from the individual is required to confirm that the variant is present.
  • This confirmation of the variant in the previously-tested individual is necessary before we can perform carrier testing or prenatal diagnosis in the family.

What information do I need to provide to order a variant confirmation test?

  • Please provide variant information to GeneDx prior to sending in the sample(s). This information may be in the form of a publication, lab report, or other communication from the laboratory, in which the variant was previously observed.
  • To clearly identify the variant, please provide:
    • For Nuclear Gene Variants:
      1. The name of the gene
      2. The variant 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 Mitochondrial (mtDNA) Variants:
      1. The name of the gene
      2. The position in the mitogenome (m.) using reference sequence NC_012920

How do I order Variant Confirmation?

  • Use a GeneDx Test Requisition Form. This test can be found in the Targeted Variant Testing section located after the main test list on all requisition forms.
    • OR Order Online by selecting the appropriate targeted test and indicate “Research confirmation” in the comments section.
  • Provide the name of the gene and name of the variant (using the format above).
  • Enclose a copy of the research report, if available.
  • For mitochondrial DNA (mtDNA) variants, select one of the Known mtDNA Variant(s) test options.
  • Please refer to our Specimen Requirements page prior to submitting a specimen:

What is the turn-around time?

  • Results are generally available in 3-4 weeks.
  • Written report(s) are sent to the ordering health care provider.