Test Method

Molecular

CPT Codes

81351

Test Description

TP53 encodes a tumor suppressor protein that normally responds to diverse cellular stresses to induce cell cycle arrest, apoptosis, senescence, DNA repair or changes in metabolism. Somatic, loss of function mutations in TP53 are one of the most frequent in cancer and result in loss of the anti-proliferative and tumor-suppressive effects of the p53 protein. In some malignancies, such as acute myeloid leukemia (AML) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), TP53 mutations are associated with an adverse prognosis resulting in the use of more aggressive treatment. Somatic mutations can also be associated with age-related clonal hematopoiesis in the absence of overt hematologic malignancy. Germline TP53 mutations are associated with Li-Fraumeni Syndrome – a familial predisposition to a variety of malignancies including sarcomas, breast carcinoma, gliomas and adrenocortical carcinomas. This DNA test is performed by targeted next-generation sequencing (NGS) and will detect mutations within the sequenced regions of TP53 exons 2 - 11 (NM_000546.5). See the table below for the specific regions sequenced by this assay. The reference genome assembly used for alignment and variant calling is hg19 (GRCh37).

Specimen Requirements

  • Bone marrow aspirate: 2-3 mL in sodium heparin (green top) preferred, or 1-2 mL in EDTA (purple top)
  • Peripheral blood: 3 mL in sodium heparin (green top) preferred, or 3 mL in EDTA (purple top)
  • Formalin-Fixed Paraffin-Embedded Tissue: Minimum 0.2 x 0.2 x 0.2 cm tissue, non-decalcified tissue only

Storage & Transport

Ship specimen the same day whenever possible, with refrigerated (not frozen) cold pack.

Label all tubes with at least two unique patient identifiers. Slides require one patient identifier. Identifiers include name, DOB, specimen ID# or medical record.

Turnaround time

5-7 days

Level of Service

Global