Most comprehensive 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/Multiplex Ligation-dependent Probe Amplification
Lavender (K2EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 2 mL)
Ambient: 1 week; Refrigerated: 1 month; Frozen: 6 months
Background Information for Li-Fraumeni (TP53) Sequencing and Deletion/Duplication:
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: 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; Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large TP53 deletions/duplications.
Analytical Sensitivity and Specificity: Greater than 95 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined. 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|
|2009314||Li-Fraumeni (TP53) Seq, DelDup Spcm|
|2009315||Li-Fraumeni (TP53) Seq, DelDup Interp|