Gene panel (includes 16 genes)
Basic characteristics of the clinical phenotype
Medulloblastoma is a primary malignant tumor of the central nervous system (CNS) that is more commonly seen in children, affecting approximately 9.6 children and 0.54 adults per million individuals. It is also reported more often in men than in women. The tumor starts in the brain, at the base of the skull (posterior fossa) and tends to spread to other areas of the brain and spinal cord. People with medulloblastoma may have problems with walking, balance, fine motor skills, headaches, nausea, seizures, and other characteristics.
Treatment usually consists of surgery to remove as much of the tumor as possible and subsequent treatment with radiation and/or chemotherapy, resulting in an improved prognosis and increased monitoring.
Most cases of medulloblastoma are considered sporadic and are stratified into molecular subgroups depending on the underlying biology and clinical characteristics of the patient. The groups are most often divided into those affecting the WNT pathway [WNT group], SHH pathway [SHH group], group 3 and group 4. However, there are also data on the association of medulloblastomas with the presence of genetic syndromes such as Gorlin syndrome, Li-Fraumeni, Fanconi anemia, familial adenomatous polyposis (FAP) and others.
The genes associated with these diseases are tumor suppressors, and mutations in them often result in loss of functional proteins, as well as missense variants and copy number changes. These variants can be either inherited or arise de novo.
Pathogenic variants in genes from this panel are thought to be responsible for approximately 5% of medulloblastoma cases.
Indications for Referral/ Clinical Significance:
Candidates for this test are all patients with a clinical (medical) or family history suggesting that the etiology of the disease is due to hereditary genetic changes. The test is offered to patients in whom the most common mutations are not detected using Sanger sequencing of the most commonly affected genes.
This test is specifically intended for the analysis of inherited germline mutations and is not suitable for the study of somatic mutations in tumor tissue.
Method: Next-generation sequencing.
The method involves bidirectional DNA sequencing of all coding exons and intron-exon boundaries of target genes. The laboratory offers Sanger sequencing of a single exon or a pair of exons in the patient's relatives to determine the carrier status in cases where the mutation is known (Test #182).
Sensitivity of the method: depends on G-C and A-T content, as well as the presence of segmentally duplicated genes
What does the test involve?
· DNA isolation and sample storage.
· Parallel sequencing including bidirectional DNA sequencing of all coding exons and intron-exon boundaries of target genes
· Bioinformatic analysis of sequencing data. For each patient, only data for the gene(s) of interest were analyzed.
· 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.