DICER1 Mutation Analysis, Next-Generation Sequencing, Tumor

Casandra

Casandra Test Code MC71453Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID DICETCPT Codes 81479, 88381

DICER1 Mutation Analysis, Next-Generation Sequencing, Tumor

Clinical Use

Use

This test is used for identifying specific mutations within the DICER1 gene to assist in tumor diagnosis and classification. It is particularly relevant for tumors associated with multiple types like embryonal rhabdomyosarcoma and Sertoli-Leydig cell tumors, and in diagnosing certain central nervous system tumors. DICER1 mutations are significant molecular biomarkers for diverse conditions such as primary intracranial sarcoma and embryonal tumors with multilayered rosettes. They are also indicative of DICER1 tumor-predisposition syndrome, which has implications for pleuropulmonary blastoma, cystic nephroma, and several other tumor types.

Special Instructions

When this test is ordered, slide review will always be performed at an additional charge. A pathology report, including details like patient name, block number, tissue collection date, and source, must accompany the specimen for testing to be performed. Tissue or cytology slides are needed to assess for somatic mutations, requiring a minimum tumor content of 20% tumor nuclei.

Limitations

The test cannot differentiate between somatic and germline alterations, and may require additional testing to clarify hereditary risk significance. It is reliable only on specimens with at least 20% tumor cells. Point mutations and small deletions-insertions in the DICER1 gene can be detected, but it does not catch multi-exon deletions, duplications, larger genomic copy number variants, or epigenetic modifications like promoter methylation. Results should be interpreted with comprehensive clinical and laboratory data, as negative results do not completely exclude the presence of undetectable variants.

Test Details

New York Approved