Whole Exome Sequencing-XL, Duo Analysis

Key Information

Lab:

Molecular

TAT:

10 weeks

Price:

Contact Lab

CPT Code(s):

81415, 81416

Test Code:

DXLD

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Whole Exome Sequencing-XL, Duo Analysis

Whole Exome Sequencing–XL (WES-XL), Duo Analysis is a comprehensive, phenotype-driven exome analysis of genomic data from the proband and one parent, to help determine the underlying genetic cause of a patient’s unexplained medical condition. Secondary findings will only be reported for the patient initially, and only variants expected to impact gene function will be included. Only SNV analysis is performed for secondary findings. The patient and/or patient’s guardian may choose whether or not to receive information related to secondary findings. If the laboratory does not have clear consent to report secondary findings, this information will not be included in the final report. If a secondary finding is identified, parents may choose to have the finding confirmed at no additional charge.

The standard WES-XL is a trio analysis that includes the proband and both parents. However, the duo analysis is available and includes samples from the proband and one parent; a sibling sample may be submitted in place of a parental sample. A separate consent and family studies form must be completed for each familial sample submitted in addition to the patient. Please contact the lab prior to sending a sibling sample.

Technical Information

Whole Exome Sequencing – XL (WES-XL) detects single nucleotide variants (SNVs) within exonic regions, intronic regions, promoters, and 3’-UTRs. SNVs are only detected in intergenic regions if the variant has been previously reported. WES-XL will detect copy number variants (CNVs). Disease-associated sequence variants in the mitochondrial genome will also be reported. WES-XL will not detect trinucleotide repeat expansions, methylation abnormalities, balanced rearrangements, and some small exonic-level copy number changes. Reanalysis can be ordered as a separate for an additional charge.

Specimen Requirements

The preferred sample type is 3-4 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA and saliva are also accepted for this test. Blood and saliva kits are available by request.
Send approximately 5µg of extracted DNA at a requested concentration of 90-130 ng/µl.
Saliva samples must be submitted in an approved saliva kit.
Saliva, saliva swabs, or extracted DNA from saliva samples may not meet the lab’s quality control threshold for sequencing on the genome platform. For saliva samples that do not meet QC standards, providers will be contacted to determine whether a new blood sample can be collected or if testing should be run on an exome platform instead. All FFPE samples will be run on an exome platform.

Transport Instructions

The blood specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.
Extracted DNA should be sent at room temperature via overnight delivery.
Saliva is stable at room temperature and can be delivered via overnight or ground shipping.

Associated Tests

Connect With Our Experts

Call 1-800-473-9411 to speak with our team of laboratory genetic counselors for questions or additional information.

Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC
Alex Finley, MS, CGC

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