VistaSeq® MLH1 Comprehensive Analysis

Whole blood or saliva collected in an Oragene Dx collection kit

10 mL whole blood, 2.0 mL saliva

7 mL whole blood, 0.5 mL saliva

Lavender-top (EDTA) tube or yellow-top (ACD) tube or Oragene Dx 500 saliva collection kit

This assay is intended for patients with a personal or family history consistent with MLH1-related Lynch syndrome.

Genes included: MLH1

Sequencing cannot detect variants in regions not covered by this analysis, including noncoding or deep intronic variants and may not reliably detect changes in repetitive elements, such as microsatellite repeats. Sequencing may not detect mosaic variants, inversions, or other genomic rearrangements such as transposable element insertions. Sequence analysis may also be affected by allele drop-out due to the presence of a rare variant under a primer site or homopolymeric regions. The method does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies.

Copy number analyses are designed to detect single exon, multi-exon, and full gene deletions or duplications. These analyses may not detect certain genomic rearrangements, such as translocations (balanced or unbalanced), inversions, or some partial exon rearrangements. This assay cannot determine exact breakpoints of deletions or duplications detected.

The presence of pseudogenes can interfere with the ability to detect variants in certain genes. For example, deletion/duplication analysis of PMS2 exons 11-15, among others, is complicated by the highly homologous PMS2CL pseudogene. Deletions/duplications in PMS2CL have not been associated with Lynch syndrome, however this assay may not be able to determine if a deletion/duplication affects PMS2 or PMS2CL.

Each gene sequence is interpreted independently of all other gene sequences; however, variants in different genes may interact to cause or modify a typically monogenic disease phenotype.

In addition, the presence of an inherited cancer syndrome due to a different genetic cause cannot be ruled out. Any interpretation given should be clinically correlated with available information about presentation and the patient's relevant family history.

This test is not intended to detect somatic variants. Bone marrow transplantation may affect the outcome of these results. Please contact Labcorp at 1-800-345-GENE to discuss testing options.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

The coding region and flanking splice sites are analyzed by NGS (+/-10bp) and deletion/duplication analysis. Exon-level deletions/duplications are assessed by aCGH. Clinically significant findings are confirmed by Sanger sequencing or qPCR. Results are reported using ACMG guidelines and nomenclature recommended by the Human Genome Variation Society (HGVS).