Characteristics of the test: (includes 1 gene)
RET (OMIM # 164761)
Basic characteristics of the clinical phenotype:
Multiple endocrine neoplasia type II (MEN2) is a group of autosomal dominant syndromic diseases associated with the manifestation of a number of neoplasias of the endocrine glands. In general, two main types are distinguished: MEN2A and MEN2B. MEN2A (Sipple syndrome) is associated with medullary thyroid carcinoma, pheochromocytoma, and parathyroid adenoma. In MEN2B, parathyroid masses are less common, but mucosal tumors, lip and eyelid changes, and skeletal abnormalities may occur.
Familial thyroid carcinoma, occurring without accompanying tumors in other endocrine glands, is sometimes considered part of MEN type 2.
Indications for referral:
RET gene testing is recommended for all patients with medullary thyroid carcinoma (MTC) regardless of the familial burden of MEN2, as 88% of familial and 1% to 7% of sporadic cases of MK carry mutations in this gene. In patients diagnosed with MEN2A/B, this percentage is 95% to 98%.
In patients with a family history of MEN2, testing may be performed to decide on preventive thyroid or parathyroid surgery.
When tested to diagnose MEN2, patients must meet the following criteria:
- Open MK
- Presence of one of the accompanying diseases:
a) pheochromocytoma
b) adenoma or hyperplasia of parathyroid glands
c) mucosal neuromas
Interpretation of results:
The detection of mutations in the RET gene allows the diagnosis of Multiple Endocrine Neoplasia (MEN) type 2 / Medullary Thyroid Carcinoma.
The genetic counselor will interpret and answer all questions about your result.
Method: Sanger sequencing; The method involves bi-directional DNA sequencing of the coding exon(s) of the RET 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 (Tests #182 and 183).
Sensitivity of the method: 99.5%
What does the test involve?
● DNA isolation and sample storage.
● Direct sequencing of target genes/gene regions to detect pathogenic mutations.
● Forming a written result of the genetic test.
● Diagnostic interpretation of results and genetic counseling.
Biological material: Venous blood (EDTA tube) or DNA isolated from venous blood. For more information, please read carefully the "Biological Material Requirements and Transport Information".
