Eurofins Biomnis code

LPWAL

Specialty

Genetics

Clinical significance

The "LPWAL" NGS panel consists of an analysis of 10 genes: MYD88, CXCR4, ARID1A, CD79A, CD79B, NOTCH2, TP53, BTK, PLCG2 and CARD11. It must be combined with a bone marrow cytogenetic study. It is used to diagnose lymphoplasmacytic lymphomas, principally Waldenström's disease. The MYD88 mutation is reported in more than 90% of cases and can be used to rule out diagnosis of LZM, for example. In more than 40% of cases, a CXCR4 mutation is observed, generally associated with a MYD88 mutation. There are also cases with CXCR4 mutation without MYD88 mutation. Mutations in the ARID1A, CD79A, CD79B and NOTCH2 genes have also been reported in Waldenström disease and may contribute to the diagnostic approach. This panel also provides a prognostic and therapeutic approach: The presence of a CXCR4 mutation is associated with a poor prognosis and represents a resistance mutation, in the same way as secondary mutations in the BTK and PLCG2 genes. TP53 mutation, although rare (2%), is associated with a poor prognosis. The association of a MYD88 mutation with the absence of a CXCR4 mutation has a favourable prognosis under BTKi, unlike the association of both MYD88 and CXCR4 mutations, which is associated with a late response to BTKi. Absence of MYD88 mutation in Waldenström disease characterises a disease with a poor prognosis and a poor response to BTKIs or to a combination of bendamustine and rituximab. The IPSSWM-R prognostic score does not currently include molecular data.

Preanalytics

• EDTA bone marrow or DNA extracted (200ng of DNA minimum)
•   Ambient temperature

• A tube specifically for this analysis : No

Further information

Samples to be collected from Monday to Friday
Sample must be refrigerated if transport is > 48 hours
Use the specific request form B8-INTGB: Malignant blood disorders
Attach:
- the results of the FBC- platelets
- the bone marrow report
- the immunophenotyping report
- Results of lymph node histology (if performed)

Specific equipment available

• S9L: Envelopes yellow for karyotypes LYON

Documents to download

• Specific request form B8-INTGB
• Panel form(DS120-INTGB)

Methodology

Method: Targeted sequencing of genes (NGS). - Library: Library Preparation Enzymatic Fragmentation Kit 2.0 Twist - NGS Platform: NovaSeq Illumina (2x150pb) - paired-end sequencing - Analysis software: Demultiplexage BCLconvert V3.10.5 / VarSome Pipeline version 11.8 (CE-IVD)

Turnaround time

10 days