MUTYH Sequencing and Deletion Duplication

Casandra

Casandra Test Code QD23850Version 1 (DRAFT)

Performing Lab

Lab Quest DiagnosticsLab Test ID 93944

MUTYH Sequencing and Deletion Duplication

Also known as: MYH Associated Polyposis, MAP

Clinical Use

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Use

This test is used to identify individuals with autosomal recessive MUTYH-associated polyposis (MAP) syndrome by detecting single‑nucleotide variants, deletions, and duplications in the MUTYH gene, which encodes the DNA repair protein MutY homolog. It is generally indicated for individuals with a personal or family history of ≥20 colorectal adenomas, colorectal cancer, or other gastrointestinal cancer. Informed consent following genetic counseling is strongly recommended, and testing should be offered ideally to the family member with the youngest age of onset of polyps or cancer.

Special Instructions

Sample reports and information regarding specific variants analyzed are available on Quest’s Hereditary Cancer website (QuestHereditaryCancer.com). The Hereditary Cancer Single Site(s) test (test code 93945) may be appropriate when a familial mutation is already known, though the MUTYH Sequencing and Deletion/Duplication test (93944) may still be indicated. Clinicians can contact Quest’s genetic counselors via Quest Genomics Client Services at 1.866.GENE.INFO. Upon receipt of a fully completed order, insurance coverage will be verified and out‑of‑pocket responsibility estimated; patients will be notified if expected responsibility exceeds $100. Results turnaround typically is completed 14 to 21 days after receipt of sample and forms, assuming complete order and no preauthorization delays.

Limitations

A positive result indicates a pathogenic or likely pathogenic variant in one or two copies of MUTYH; two variants indicate diagnosis of autosomal recessive MAP, but does not diagnose cancer or polyps. A negative result indicates no detected pathogenic or likely pathogenic variants, but clinical suspicion may persist; additional criteria or testing may be considered. Variants of uncertain significance (VUS) reflect unclear or novel variants; variant classification may change over time, and providers are encouraged to check annually (e.g., via VariantIQ). Interpretation relies on current evidence and may evolve. Official reports include methods and limitations; clinical decision-making should consider personal and family history.

Test Details