Family Member Previously Tested – Outside Laboratory

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.

What information do I need to provide to order targeted variant testing on an individual when their family member was tested at another diagnostic laboratory?

  • If available, please submit the outside molecular diagnostics laboratory report on the family member.
  • If this is not available, please identify the variant:
    • 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 targeted variant testing on an individual when their family member was tested at another diagnostic laboratory?

  • Use a GeneDx Test Requisition Form or order online.
  • Select Targeted Variant Testing (Inherited Cancer Requisition) or Targeted Variant Testing and Special Services (all other requisitions).
  • Provide the name of the gene and name of the variant (using the format above).
  • Enclose a copy of the outside diagnostics laboratory 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: https://www.genedx.com/specimen-requirements/

Is a positive control required?

  • No, a positive control is not required but it is highly recommended.*
  • Without a positive control, we may not be able to confirm that a negative result is truly negative.
  • Please label the test requisition form for the positive control individual with “Positive Control Only – No Report”.
  • If requested, a report for the positive control family member is available for an additional fee.
  • Please call one of our genetic counselors if you would like to discuss the submission of a positive control.

*A positive control is not needed for mtDNA variants

What is the turn-around time?

  • Results are generally available in 2-3 weeks.
  • Written report(s) are sent to the ordering health care provider.