Interpretation of ambiguous TP53 test results: Mosaicism, clonal hematopoiesis, and variants of uncertain significance.

The increased use of next-generation sequencing has led to the detection of pathogenic TP53 variants in the germline setting in patients without a personal or family history consistent with Li-Fraumeni syndrome (LFS). These variants can represent low-penetrance LFS, mosaic LFS, or clonal hematopoiesis of indeterminate potential. Additionally, TP53 variants of uncertain significance can be detected in patients with a history suspicious for LFS. The interpretation of the significance of these variants can be challenging but is crucial for an accurate diagnosis and appropriate medical management. This retrospective case review provides illustrative examples of the interpretation of challenging TP53 results through multidisciplinary expertise and use of a flowchart. The authors describe eight patients with TP53 variants associated with ambiguous diagnoses and, for each case, describe how the results were interpreted and the medical care that was implemented. This report presents illustrative cases to help guide clinicians to reach definitive diagnoses for patients when confronted with TP53 variants that are inconsistent with the clinical picture and to add to the body of literature regarding interpretation and medical management of TP53 variants discovered on germline testing.

Six case reports of NTHL1-associated tumor syndrome further support it as a multi-tumor predisposition syndrome.

NTHL1-associated tumor syndrome (NATS) is an autosomal recessive condition characterized by an increased risk for colorectal polyposis and colorectal cancer (CRC). Only 46 case reports have been previously published. In a retrospective review, we analyzed the clinical histories of six patients found to have NATS after genetic counseling and testing. NATS appears to be associated with an increased risk for colorectal polyposis, CRC, female breast cancer, meningiomas, and endometrial cancer. Although research is limited, prior publications have reported a multi-tumor predisposition for individuals with biallelic pathogenic or likely pathogenic variants in NTHL1. Additional data are necessary to further define the cancer risks so affected individuals can be appropriately managed.

Revising the FOCUS framework through a qualitative study assessing self-reported counseling skills of genetic counselors.

Frameworks have been developed to help conceptualize clinical genetic counseling (GC), and observational studies have helped understand the process and content of GC sessions. However, additional research is needed to identify GC skills (behaviors or strategies) that practicing genetic counselors report consciously using to meet certain GC goals and determine what common terminology, if any, is being used to describe the various skills. Nineteen practicing genetic counselors in prenatal, pediatric, or cancer specialties were interviewed to elicit how they achieve session goals. Interview recordings were transcribed, coded thematically, and categorized using process categories from the communication strategy domain of the Framework for Outcomes in Clinical Communication Services (FOCUS). Reported skills largely fit within FOCUS, though findings prompted minor modifications of several FOCUS process categories and consolidation of the categories from 13 into 10. Although genetic counselor respondents reported a broad range of strategies and behaviors, they rarely had terms for skills they described. Results reveal concrete examples of GC skills, provide evidence for refinement of FOCUS, and highlight the need for establishing common terminology to describe these skills.