Hereditary Diffuse Gastric Cancer Syndrome, CDH1, Full Gene Analysis, Varies

Casandra

Casandra Test Code MC89893Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID CDHZCPT Code 81406

Hereditary Diffuse Gastric Cancer Syndrome, CDH1, Full Gene Analysis, Varies

Clinical Use

Use

This test is useful for evaluating patients with a personal or family history suggestive of hereditary diffuse gastric cancer (HDGC) syndrome. It aids in establishing a diagnosis of HDGC syndrome, allowing for targeted cancer surveillance based on associated risks. The test also helps in identifying genetic variants associated with an increased risk for HDGC syndrome, enabling predictive testing of at-risk family members.

Special Instructions

This test does not include CTNNA1, another gene associated with hereditary diffuse gastric cancer. For a comprehensive panel that includes the CDH1 gene, consider ordering CRCGP or BRGYP tests. Due to potential DNA interference, patients who have undergone a hematopoietic stem cell transplant require specific consultation. New York clients must submit informed consent for genetic testing. Specimens are preferred to be received within 24-30 days, depending on type, and maternal cell contamination studies are required for certain specimen types.

Limitations

Next-generation sequencing may not detect all genomic variants, with certain regions being less reliably covered. False-negative or positive results are possible, and some regions may not be evaluated due to technical limitations such as homology or high GC content. The test detects up to 95% deletions and insertions under 75bp; however, larger or mosaic variants may be missed. Interpretation assumes no recent blood transfusion or stem cell transplant involvement, as these can skew results. Not all deletion/duplication events extending beyond target panels are reported.

Test Details

New York Approved