Transcriptome Sequencing
Transcriptome sequencing, also known as RNA-seq, is a powerful addition to genetic testing. It has been reported to significantly enhance the diagnostic rate (by 7.5%–36%) depending on the clinical phenotype and tissue sample. RNA-seq aids in prioritizing and resolving VUS (Murdock et al, 2021; PMID: 33001864).
Multiple studies have shown the utility of functional studies such as RNA-seq in deciphering disease-causing non coding or synonymous splicing variants (PMID: 35946377; 35063693). For example, Wai et al (2020; PMID: 32123317) found that 33% of VUS alter splicing; this is significant since variants impacting splicing have a greater likelihood of being pathogenic.
Turnaround time is 8 weeks.
Who is this test for?
- Patients who have had panel, exome, or genome sequencing and have one or more VUS that: i) are potentially causative of altered splicing, and ii) occur in a gene in which variation has been associated with the clinical presentation.
- Research study samples
Sequencing & Interpretation
Prior to performing RNA sequencing, clinical Sanger sequencing will be done to confirm the presence of the variant. Such confirmation supports reclassification following completion of the transcriptome analysis. Sanger validation will not be done on research samples.
Total RNA is isolated from whole blood samples (see Samples tab for collection requirements) and then subjected to globin depletion and polyA selection to enrich mRNA for cDNA library construction and sequencing.
Test Limitations
Transcriptome sequencing is presently performed in a research capacity and is not yet accredited or licensed for clinical diagnostic use. Classification of gene variants using data generated by this test is based on our current understanding of RNA splicing and expression. Variant classification relies on current knowledge of RNA splicing and expression, which is evolving over time.
Samples & Ordering
Requirements
- 1 tube (2mL-4.0mL) of whole blood drawn in a PAXgene/Tempus RNA tube
- This tube/kit can be ordered through our kit order page
- Samples should be shipped at ambient temperature (18-25℃) or refrigerated (2-8℃)
- Whole blood is stable for 5 days at ambient temperature (18-25℃) or 7 days refrigerated (2-8℃). Do not freeze.
Shipping Address
Alamya Health
℅ Breakthrough Genomics
2 Hughes, #100
Irvine, CA 92618