TPMT GENOTYPING

GENOTYPE DETECTED: 2W, 2M, 3B and 3C of Thiopurine methyl-transferase gene

INDICATIONS FOR ORDERING: Detection of TPMT enzymatic activity before starting the treatment with drugs like Azathiopurine or Mercaptopurine in paediatric patients

METHOD USED: Qualitative detection of TPMT gene mutation using gel electrophoresis

• SPECIMENS: Type, storage and transport
  Type: Non-diluted peripheral blood or bone marrow aspirate in EDTA (lavender) tube. PLEASE AVOID HEPARINATED SAMPLES

Bone Marrow: 3 mL
Whole Blood: 3 mL

• Storage: Whole Blood or Bone Marrow: Separate specimens must be submitted when multiple tests are ordered.
• Extracted DNA: Separate specimens must be submitted when multiple tests are ordered
• Unacceptable samples: Specimens collected in anticoagulants other than EDTA, haemolysed/clotted samples.

TEST DESCRIPTION: This is a DNA-based qualitative PCR assay. The DNA extracted is employed into the genomic PCR with specific in-house designed primers [2W, 2M, 3B (460bp), 3C (719bp)]. Then the PCR products of 3B and 3C are digested in conventional PCR using DNA polymerase enzyme. Samples are run along with the positive and biologically negative control on gel electrophoresis.
This test only detects the mutation of the TPMT gene, and not recommended for monitoring of molecular drug for the therapeutics

ANALYTICAL SENSITIVITY: This is qualitative test, hence yields a positive or a negative result only. Analytical sensitivity refers to the limit of detection of any assay and hence may not be applicable in this context

TURNAROUND TIME: 5 (five) working days from receipt of sample

QUALITY ASSURANCE & COMPETENCY TESTING: Regular internal quality checks and intra-lab comparisons are performed to ensure accurate and precise results. Highly trained personnel performing this test undergo regular competency assessments and attend regular conferences and educational programs in order to stay upbeat with the newer advances in the biology and diagnostics of the disease in question.

ACCREDIATION: NABL