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.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 2 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
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.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2009314||Li-Fraumeni (TP53) Seq, DelDup Spcm|
|2009315||Li-Fraumeni (TP53) Seq, DelDup Interp|