Known Variant Testing (KT2)
Information for Ordering
Acceptable Specimen Types
- Fresh blood sample: 3–6 mL EDTA; no time limitations associated with receipt
- Saliva: OGD-575 DNA Genotek collection kit; kits are provided upon request
- DNA extracted from lymphocyte cells: minimum volume of 25 µL containing 3 µg of DNA; A260/A280 ratio ≥1.8; must be extracted in a CLIA-certified or equivalent laboratory
Turnaround Time
Average turnaround time: 15 working days
Price, CPT Code, and Z Code
Price: $250 USD institutional/self-pay price
CPT code: 81403
Z code: ZB67K
Candidates for Testing
Patients preparing for prenatal or preimplantation genetic testing and individuals at risk of inheriting a previously identified variant.
Specimen Shipping and Handling
Please review the specimen requirements listed above.
All submitted specimens must be shipped at room temperature. Do not ship specimens on ice.
Specimens must be packaged to prevent breakage. Absorbent material must be included to contain liquids if breakage occurs. Specimens must also be shipped in double watertight containers, such as a specimen pouch placed inside the shipping company’s diagnostic envelope.
To request a sample collection kit, please complete the Collection Kit Request Form or email medgenomics@uabmc.edu.
Before shipping a specimen, please contact the MGL by email at medgenomics@uabmc.edu or by phone at 205-934-5562. Please provide the shipment date and package tracking number so the laboratory can help ensure receipt.
Required Forms
Other phenotypic checklists:
- NF2 and Schwannomatosis Phenotypic Checklist
- SMARCB1 / ATRT Phenotypic Checklist
- TSC Phenotypic Checklist
- PTEN Phenotypic Checklist
About
Test Description
We offer targeted detection of a specific, previously characterized variant in any gene for which testing is available in our laboratory. From a fresh EDTA blood sample, analysis may be performed by Sanger sequencing, MLPA, and/or FISH. To offer this testing service, the proband’s variant must have been identified by our laboratory before testing relatives.
Important Information Regarding NF1
With the largest dataset of NF1 genotypes matched with phenotypes, any identified genotype-phenotype correlations will be reported in real time. Confirmatory testing of reportable variants is performed using orthogonal methods as needed.
For novel NF1 variants of uncertain significance, we offer targeted RNA-based testing at no charge to assess the effect of the variant on splicing and support accurate classification and interpretation.
First-degree relatives of a proband with a novel or previously identified variant of uncertain significance may be offered targeted analysis at no charge when accurate phenotypic information is provided by a healthcare professional. Testing of additional relatives at no charge is at the discretion of the Laboratory Director.
Mosaicism is often present in sporadic patients with an NF1 microdeletion and may have important implications for genetic counseling. Evaluation by FISH analysis of 200 interphase cells may be offered in these cases.
View references for this testing .
Other Related Test Options
- Prenatal Known Variant Testing (PT2)
- RNA-based Known Variant Testing (RT2)
- Next-Generation Sequencing-Based Known Variant Testing (KT2-NG)
For more information, test requisition forms, or collection kits, please contact the UAB Medical Genomics Laboratory at 205-934-5562 or medgenomics@uabmc.edu.