T Cell Gene Rearrangements (TCR)

Molecular Haematology

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Description

TCR BetaUsing RT-PCR it is possible to perform V-C amplification as the constant region is brought into contact with V-D-J rearrangement during RNA transcription. RT-PCR is thought to improve detection - the primers are used to amplify across V-D-J-C junction producing a ladder of fragments differing in size largely because of random insertion of nucleotides at individual joins - a normal distribution of fragments is predicted for a polyclonal population. When a T cell clone is present a band from the junction of identical clonal cells is over represented.The polymerase chain reaction ( PCR ) procedure allows the study of genetic disease as DNA fragments of interest can be amplified to the extent that it can be analysed directly even from minute amounts of starting material.TCR GammaIn this system TCRg gene found on chromosome 7 is amplified in a PCR multiplex. The TCRg gene consists of two constant regions ( C1, C2 ), five joining regions ( J1, J2, JP, JP1, JP2 ) and fourteen variable regions, subdivided into four subgroups: VgI - V1, V2, V3, V4, V5, V6, V7, V8 VgII - V9 VgIII - V10 VgIV - V11This multiplex system employs primers to V2, V3, V4, V5, V8, V9, V10, V11 and three J region primers JGT1, 2 ( J1,J2 ), JGT3 ( JP1,JP2 ) and JGT4,( JP ). V2 and V8 have high sequence homology and may amplify the same allele.

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Indications

Used to diagnose and monitor clonal T cell populations.

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Sample Type

5ml EDTA blood or bone marrow, less than 48 hrs old.

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Turnaround Time

Within 4 weeks

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Testing Frequency

As required.

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External Notes

Level of detection TCR beta 1:104, TCR gamma 1:103 clonal cells to normal cells.

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Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.