Appropriate initial test for Li-Fraumeni syndrome (LFS). Should not be used to detect somatic TP53 variants associated with malignancy. Not recommended for patients with a hematologic malignancy and/or who have undergone allogeneic stem cell transplantation.
Polymerase Chain Reaction/Sequencing
Lavender (K2EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 1 mL)
Ambient: 1 week; Refrigerated: 1 month; Frozen: 6 months
Background Information for Li-Fraumeni (TP53) Sequencing:
Characteristics: Predisposition for developing early-onset and multiple primary cancers, particularly soft tissue and bone sarcomas, adrenocortical carcinoma, brain tumors, premenopausal breast cancer, and other malignancies.
Prevalence: 1 in 5,000 - 1 in 20,000.
Inheritance: Autosomal dominant.
Penetrance: Approximately 50 percent by age 30 years and 90 percent by age 60 years.
Cause: Pathogenic germline mutations in the TP53 gene.
Clinical Sensitivity: Approximately 80 percent for individuals meeting classic Li-Fraumeni syndrome (LFS) criteria.
Methodology: Bidirectional sequencing of all coding regions and intron-exon boundaries of the TP53 gene.
Analytical Sensitivity and Specificity: Greater than 95 percent.
Limitations: TP53 gene regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. Diagnostic errors can occur due to rare sequence variations. This assay is not designed to detect somatic variants associated with malignancy. Interpretation of this test result may be impacted if the patient has had an allogeneic stem cell transplantation.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|2009303||Li-Fraumeni (TP53) Sequencing Specimen|
|2009304||Li-Fraumeni (TP53) Sequencing Interp|