Characteristics of the test: (includes 1 gene – screening for most common mutations)
TP53 (OMIM #191170) – exons 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11
Basic characteristics of the clinical phenotype:
Li-Fraumeni syndrome (LFS; OMIM #151623) is a hereditary cancer syndrome in which single to multiple neoplasias occur at an early age. The most common neoplasias, associated with LFS, are premenopausal breast cancer, osteosarcoma, rhabdomyosarcoma, adrenocortical carcinoma, and tumors of the central nervous system. Less common are melanoma, gastrointestinal tumors and Wilms tumor. The average age of onset of malignancy in LFS patients is between 20 and 45 years. Li-Fraumeni syndrome is characterized by an autosomal dominant inheritance pattern.
Mutations in TP53 can be inherited or arise de novo early in embryogenesis or in one of the parental germ cells. The risk of developing tumors in TP53 mutation carriers has been determined to be ~73% for men and nearly 100% for women.
Indications for referral:
Patient with a history of a tumor belonging to the tumor spectrum of Li-Fraumeni syndrome: soft tissue sarcoma, osteosarcoma, premenopausal breast cancer, central nervous system tumors, adrenocortical carcinoma, leukemia or bronchoalveolar lung cancer - diagnosed before 36 years old.
and at least one of the following:
- at least one first- or second-degree relative with an oncological disease not necessarily matching that of the proband (except for breast cancer if the proband has that type of diagnosed cancer) before the age of 46 years or with multiple tumors
- patient with multiple tumors (excluding breast tumors), two of which belong to the LFS tumor spectrum, the first of which occurred before the age of 46
- a patient who is diagnosed with adrenal gland carcinoma or choroid plexus carcinomas regardless of family history.
Interpretation of results:
The detection of point mutations and small deletions/insertions in the genes of the panel will allow a genetic diagnosis to be made.
The genetic counselor will interpret and answer all questions about your result.
Method: Sanger sequencing.
The method involves bi-directional DNA sequencing of all coding exons and intron-exon boundaries of the TP53 gene. The laboratory offers single exon or exon pair sequencing in relatives of patients to determine carrier status in cases where the mutation is known (Test #182, 183).
Sensitivity of the method: 99.5%
What does the test involve?
DNA isolation and sample storage.
Direct sequencing of target genes/gene regions for detection of pathogenic mutations.
Forming a written result of the genetic test.
Diagnostic interpretation of results and genetic counseling.
Biological material: Venous blood or DNA
For more information, please read the "Biological material requirements and shipping information" carefully.
