T-cell receptor gamma (TRG) gene rearrangement NGS

Diagnostic Use

Detection or exclusion of T-cell clonal populations.

This test detects clonality to a level of 2.5% (5% of cells containing a heterozygous rearrangement).

Department

Genetics - Molecular Oncology

Delphic Registration Code

MONC

Laboratory Handling

Phlebotomy

2x EDTA (Lavender) dedicated to Genetics

Registration

Send to MONC

Synonyms

T cell receptor gene rearrangement

Turnaround Time

21 days

Test Code

5225

Specimen Type

• Whole Blood
• Bone Marrow
• Tissue

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Acceptable

• Pottle
• RPMI (Bone Marrow)

Preferred Sample Volume (ml)

8

Minimum Sample Volume (ml)

4

Interferences

Clonality detection using this technique may be influenced by the T cell content of the sample and pseudoclonality may occur in samples with low T cell content.

Additional Specimen Information

4-8 ml peripheral blood in EDTA. 1-3 ml of bone marrow in EDTA or RPMI (anticoagulant).
5 mm cube of fresh (in saline or RPMI) or frozen tissue.
FFPET - block or at least 5 x 10 micron slices

Aliquot Instructions

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

Paraffin-embedded tissue may, or may not, yield DNA of a suitable quality or quantity for this assay and may be reported as insufficient.

Urgent testing is available by prior arrangement. Please contact the laboratory to request urgent testing on 03 378 6007.

Interpretation

Clonal populations of cells yield one (monoclonal), two (clonal) or more (oligoclonal) rearrangements. A normal population of T cells will produce a polyclonal pattern representing a heterogeneous population.

Clonality is determined if the most frequent rearrangement was present at 2.5% or greater and 2-fold that of the polyclonal background.

Reference Intervals

The sensitivity and specificity of this test compared to clinicopathologic information is ~85% and 92% respectively, as assessed by a small in-house verification (n = 26).

Test Method

The T-cell receptor gamma (TRG) gene locus is analysed using multiplex PCR (Lymphotrack TRG assay, Invivoscribe Inc) and next generation sequencing on an Illumina MiSeq instrument. Secondary sequencing analysis is performed using Lymphotrack Dx software.

Non-Funded Test Cost

$638.12 (Exclusive of GST)

Billing Code

5225

Contact Information

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