Exome-based cancer predisposition gene testing can provide a genetic diagnosis for individuals with heterogeneous tumor phenotypes.

The development of multiple primary tumors is one of the hallmarks of hereditary cancer. The phenotypic presentation of individuals with multiple primary tumors is often heterogeneous, which hampers the establishment of a genetic diagnosis. The absence of a genetic diagnosis may lead to inappropriate surveillance advices and treatment choices.

Germline Pathogenic Variants in Patients with Pancreatic Ductal Adenocarcinoma and Extra-Pancreatic Malignancies: A Nationwide Database Analysis.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease. Approximately 10% of affected individuals have an inherited component. Deleterious germline variants increase the lifetime risk for PDAC and are often associated with an elevated risk for extra-pancreatic malignancies.

A germline PDGFRB splice site variant associated with infantile myofibromatosis and resistance to imatinib.

Purpose: Infantile myofibromatosis is characterized by the development of myofibroblastic tumors in young children. In most cases, the disease is caused by somatic gain-of-function variants in platelet-derived growth factor (PDGF) receptor beta (PDGFRB). Here, we reported a novel germline intronic PDGFRB variant, c.

Genomic instability in non-breast or ovarian malignancies of individuals with germline pathogenic variants in BRCA1/2.

Background: Individuals with germline pathogenic variants in BRCA1 or BRCA2 are at a high risk of breast and ovarian carcinomas with BRCA1/2 deficiency and homologous recombination deficiency that can be detected by analysis of genome-wide genomic instability features such as large-scale state transitions, telomeric allelic imbalances, and genomic loss of heterozygosity. Malignancies with homologous recombination deficiency are more sensitive to platinum-based therapies and poly(ADP-ribose) polymerase inhibitors. We investigated the fraction of non-breast or ovarian malignancies that have BRCA1/2 deficiency and genomic instability features.

Histopathological phenotyping of cancers in PTEN Hamartoma Tumor Syndrome for improved recognition: A single-center study.

PTEN hamartoma tumor syndrome (PHTS) has a broad clinical spectrum including various benign and malignant tumors at varying age of diagnosis. Many patients remain unrecognized, unaware of their increased cancer risk. We aimed to describe the cancer spectrum, age of onset and histopathological cancer characteristics to assess whether specific cancer characteristics could improve PHTS recognition.

Cancer risks for other sites in addition to breast in CHEK2 c.1100delC families.

Purpose: Female CHEK2 c.1100delC heterozygotes are eligible for additional breast surveillance because of an increased breast cancer risk. Increased risks for other cancers have been reported.

Lifestyle Factors and Breast Cancer in Females with PTEN Hamartoma Tumor Syndrome (PHTS).

Females with PTEN Hamartoma Tumor Syndrome (PHTS) have breast cancer risks up to 76%. This study assessed associations between breast cancer and lifestyle in European female adult PHTS patients. Data were collected via patient questionnaires (July 2020-March 2023) and genetic diagnoses from medical files.

The heterogeneous cancer phenotype of individuals with biallelic germline pathogenic variants in CHEK2.

Purpose: Females with biallelic CHEK2 germline pathogenic variants (gPVs) more often develop multiple breast cancers than individuals with monoallelic CHEK2 gPVs. This study is aimed at expanding the knowledge on the occurrence of other malignancies.

Methods: Exome sequencing of individuals who developed multiple primary malignancies identified 3 individuals with the CHEK2 (NM_007194.

Microsatellite instability in noncolorectal and nonendometrial malignancies in patients with Lynch syndrome.

Background: Individuals with Lynch syndrome are at increased hereditary risk of colorectal and endometrial carcinomas with microsatellite instability (MSI-H) and mismatch repair-deficiency (dMMR), which make these tumors vulnerable to therapy with immune checkpoint inhibitors. Our aim is to assess how often other tumor types in these individuals share these characteristics.

Methods: We retrieved the full tumor history of a historical clinic-based cohort of 1745 individuals with Lynch syndrome and calculated the standardized incidence ratio for all tumor types.

Optimising clinical care through -specific germline variant curation: improvement of clinical assertions and updated curation guidelines.

Background: Germline pathogenic variants in are associated with increased risk of diffuse gastric cancer and lobular breast cancer. Risk reduction strategies include consideration of prophylactic surgery, thereby making accurate interpretation of germline variants critical for physicians deciding on these procedures. The Clinical Genome Resource (ClinGen) Variant Curation Expert Panel (VCEP) developed specifications for variant curation with a goal to resolve variants of uncertain significance (VUS) and with ClinVar conflicting interpretations and continues to update these specifications.

PRDM10 directs FLCN expression in a novel disorder overlapping with Birt-Hogg-Dubé syndrome and familial lipomatosis.

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant disorder characterized by fibrofolliculomas, pulmonary cysts, pneumothoraces and renal cell carcinomas. Here, we reveal a novel hereditary disorder in a family with skin and mucosal lesions, extensive lipomatosis and renal cell carcinomas. The proband was initially diagnosed with BHD based on the presence of fibrofolliculomas, but no pathogenic germline variant was detected in FLCN, the gene associated with BHD.

Cancer risks by sex and variant type in PTEN hamartoma tumor syndrome.

Background: PTEN Hamartoma Tumor Syndrome (PHTS) is a rare syndrome with a broad phenotypic spectrum, including increased risks of breast (BC, 67%-78% at age 60 years), endometrial (EC, 19%-28%), and thyroid cancer (TC, 6%-38%). Current risks are likely overestimated due to ascertainment bias. We aimed to provide more accurate and personalized cancer risks.

Catch them if you are aware: PTEN postzygotic mosaicism in clinically suspicious patients with PTEN Hamartoma Tumour Syndrome and literature review.

PTEN germline variants cause PTEN Hamartoma Tumour Syndrome (PHTS). Of individuals fulfilling diagnostic criteria, 41-88% test negative for PTEN germline variants, while mosaicism could be an explanation. Here we describe two individuals with PTEN mosaicism.

Optical genome mapping identifies a germline retrotransposon insertion in SMARCB1 in two siblings with atypical teratoid rhabdoid tumors.

In a subset of pediatric cancers, a germline cancer predisposition is highly suspected based on clinical and pathological findings, but genetic evidence is lacking, which hampers genetic counseling and predictive testing in the families involved. We describe a family with two siblings born from healthy parents who were both neonatally diagnosed with atypical teratoid rhabdoid tumor (ATRT). This rare and aggressive pediatric tumor is associated with biallelic inactivation of SMARCB1, and in 30% of the cases, a predisposing germline mutation is involved.

Breast Cancer Risk Genes - Association Analysis in More than 113,000 Women.

Background: Genetic testing for breast cancer susceptibility is widely used, but for many genes, evidence of an association with breast cancer is weak, underlying risk estimates are imprecise, and reliable subtype-specific risk estimates are lacking.

Methods: We used a panel of 34 putative susceptibility genes to perform sequencing on samples from 60,466 women with breast cancer and 53,461 controls. In separate analyses for protein-truncating variants and rare missense variants in these genes, we estimated odds ratios for breast cancer overall and tumor subtypes.