In order to ensure 2023 billing, testing must be activated before the end of the year, or within 30 days of proband sample collection (if sample was collected in 2023). For Exome, Genome, or Xpanded testing, if you do not expect parental samples to be received in time for testing to be activated with 2023 billing, please contact us at firstname.lastname@example.org to determine how to proceed.
GeneDx can isolate DNA directly from skin punch biopsies or from cultured fibroblasts. DNA from cultured fibroblasts is the required specimen type if the patient has had an allogeneic bone marrow/stem cell transplant and is preferred for patients with certain hematologic malignancies. Direct DNA isolation (without culturing) may be preferred for other scenarios.
Please contact email@example.com prior to specimen collection and submission if you wish to review required sample types or processing of a skin punch biopsy. WE STRONGLY ENCOURAGE CLIENTS TO CONTACT GENEDX AT firstname.lastname@example.org FOR ANY ALTERNATIVE SPECIMEN QUESTIONS.
Punch biopsy kits are available for US and Canadian clients. To order a kit, please email email@example.com or call us at 888-728-1206/301-519-2100. Contents include 15mL tube of transport media, label for tube, and prepaid return FedEx packaging. Note that kits must be refrigerated once they arrive at their destination to prevent the RPM1 media from spoiling. Kits include an expiration date, typically several weeks out from the date of shipment.
One or two 4mm skin punch biopsies. Biopsies may be collected from any site of healthy skin. One punch typically provides ample DNA for genetic testing; however, a second specimen increases the likelihood of successfully culturing. For mosaic skin disorders, be sure to biopsy an affected (lesional) area and always send two punches of 4-6 mm or excised skin of an equivalent area.
Label with the patient name plus a second identifier such as date of birth, specimen ID or medical record number. Name and 2nd identifier on the specimen label must match what is on the test order.
Stability & shipping
Skin biopsy specimens must be shipped at room temperature for overnight delivery to GeneDx the same day as the biopsy is performed. Note that specimens are accepted by the lab on Saturdays. For DIRECT DNA ISOLATION only, if shipping must be postponed, biopsies can be flash frozen and shipped frozen at a later time.
Published turn-around times do not apply for punch biopsy specimens due to the time needed to culture fibroblasts. In general cell culturing adds 2 weeks to published turn-around times.