Panel Description

The thiopurine drugs are useful in the treatment of acute lymphoblastic leukemia. Genetic variants in NUDT15 that decrease this activity are strongly associated with thiopurine-related myelosuppression. Preemptive genotyping of NUDT15 allows identification of patients who are at risk for increased toxicity resulting from use of MP, so that the starting dose of MP can be appropriately adjusted, or an alternative therapy may be considered.

This test specifically targets the following variants:
1.  NM_018283.1:c.415C>T (p.Arg139Cys)
2. NM_018283.1:c.416G>A (p.Arg139His)
3. NM_018283.1:c.52G>A (p.Val18Ile)
4. NM_018283.1:c.50_55dup (p.Gly17_Val18dup)

This test is relevant for patients with acute lymphoblastic leukemia (ALL), for which thiopurines (e.g., mercaptopurine) are used in treatment.

Understanding your patient’s potential response to thiopurines before engaging in treatment is essential for predicting whether your patient will experience reduced tolerance and/or increased toxicity to the drug, which increases patient quality and efficiency of care.

Test Description

  • Rush / STAT
2 – 3 weeks
Call for details
NUDT15 ( 1 gene )
Blood (two 4ml EDTA tubes, lavender top) or Extracted DNA (3ug in EB buffer) or Buccal Swab or Saliva (kits available upon request)
All sequencing technologies have limitations. This analysis is performed by Next Generation Sequencing (NGS) and is designed to examine coding regions and splicing junctions. Although next generation sequencing technologies and our bioinformatics analysis significantly reduce the contribution of pseudogene sequences or other highly-homologous sequences, these may still occasionally interfere with the technical ability of the assay to identify pathogenic variant alleles in both sequencing and deletion/duplication analyses. Sanger sequencing is used to confirm variants with low quality scores and to meet coverage standards. If ordered, deletion/duplication analysis can identify alterations of genomic regions which include one whole gene (buccal swab specimens and whole blood specimens) and are two or more contiguous exons in size (whole blood specimens only); single exon deletions or duplications may occasionally be identified, but are not routinely detected by this test. Identified putative deletions or duplications are confirmed by an orthogonal method (qPCR or MLPA). This assay will not detect certain types of genomic alterations which may cause disease such as, but not limited to, translocations or inversions, repeat expansions (eg. trinucleotides or hexanucleotides), alterations in most regulatory regions (promoter regions) or deep intronic regions (greater than 20bp from an exon). This assay is not designed or validated for the detection of somatic mosaicism or somatic mutations.