Does a proactive procedure lead to a higher uptake of predictive testing in families with a pathogenic BRCA1/BRCA2 variant? A family cancer clinic evaluation.

The uptake of genetic counseling and predictive genetic testing by family members at risk for hereditary tumor syndromes is generally below 50%. To address this issue, a new guideline was introduced in the Netherlands in 2019 that aims to improve the sharing of information within families. In addition to cascade screening supported by follow-up telephone calls with the proband, municipal records were accessed to allow the geneticist to contact at-risk family members directly.

Update of penetrance estimates in Birt-Hogg-Dubé syndrome.

Background: Birt-Hogg-Dubé (BHD) syndrome is a rare genetic syndrome caused by pathogenic or likely pathogenic germline variants in the gene. Patients with BHD syndrome have an increased risk of fibrofolliculomas, pulmonary cysts, pneumothorax and renal cell carcinoma. There is debate regarding whether colonic polyps should be added to the criteria.

Familial multiple discoid fibromas is linked to a locus on chromosome 5 including the FNIP1 gene.

Previously, we reported a series of families presenting with trichodiscomas, inherited in an autosomal dominant pattern. The phenotype was named familial multiple discoid fibromas (FMDF). The genetic cause of FMDF remained unknown so far.

Challenges in breast cancer genetic testing. A call for novel forms of multidisciplinary care and long-term evaluation.

Current methods of next generation sequencing may simultaneously detect multiple germline breast cancer susceptibility variants. However, it is a challenge to maximize the clinical benefit of genetic analysis for patients and family members while minimizing potentially harmful effects. Relevant issues include criteria for referral, the choice of gene panel, handling of variants of unknown significance, cancer risk counselling in clinical context including family history data, risks of tumours other than breast cancer, handling of potential germline findings revealed by tumour testing and the clinical management of gene variant carriers, including surveillance, targeted therapy, radiotherapy and risk-reducing surgery.

Oral contraceptive use and ovarian cancer risk for BRCA1/2 mutation carriers: an international cohort study.

Background: Ovarian cancer risk in BRCA1 and BRCA2 mutation carriers has been shown to decrease with longer duration of oral contraceptive use. Although the effects of using oral contraceptives in the general population are well established (approximately 50% risk reduction in ovarian cancer), the estimated risk reduction in mutation carriers is much less precise because of potential bias and small sample sizes. In addition, only a few studies on oral contraceptive use have examined the associations of duration of use, time since last use, starting age, and calendar year of start with risk of ovarian cancer.

The uptake of predictive DNA testing in 40 families with a pathogenic BRCA1/BRCA2 variant. An evaluation of the proband-mediated procedure.

When hereditary breast and ovarian cancer (HBOC) due to a BRCA1/BRCA2 germline pathogenic variant is diagnosed, the proband will be asked to inform other at-risk family members. In the Netherlands, a guideline was introduced in 2012 which provided detailed recommendations regarding this proband-mediated procedure. We now evaluated the uptake of predictive BRCA1/BRCA2 testing in 40 consecutive HBOC families diagnosed in our centre in 2014.

Do Preferred Risk Formats Lead to Better Understanding? A Multicenter Controlled Trial on Communicating Familial Breast Cancer Risks Using Different Risk Formats.

Purpose: Counselees' preferences are considered important for the choice of risk communication format and for improving patient-centered care. We here report on counselees' preferences for how risks are presented in familial breast cancer counseling and the impact of this preferred format on their understanding of risk.

Patients And Methods: As part of a practice-based randomized controlled trial, 326 unaffected women with a family history of breast cancer received their lifetime risk in one of five presentation formats after standard genetic counseling in three Dutch familial cancer clinics: 1) in percentages, 2) in frequencies ("X out of 100"), 3) in frequencies plus graphical format (10×10 human icons), 4) in frequencies and 10-year age-related risk and 5) in frequencies and 10-year age-related risk plus graphical format.

[BRCAmutations more frequent in people of Jewish ancestry].

Three BRCA1/BRCA2 mutations occur more frequently in the Jewish population than in the general population. In Jewish patients with breast cancer about 10% of cases are caused by one of these mutations; consequently, all patients with breast cancer and who are of Jewish ancestry, or their healthy family members, are eligible for genetic testing.

Constitutional mismatch repair deficiency as a differential diagnosis of neurofibromatosis type 1: consensus guidelines for testing a child without malignancy.

Constitutional mismatch repair deficiency (CMMRD) is a rare childhood cancer predisposition syndrome caused by biallelic germline mutations in one of four mismatch-repair genes. Besides very high tumour risks, CMMRD phenotypes are often characterised by the presence of signs reminiscent of neurofibromatosis type 1 (NF1). Because NF1 signs may be present prior to tumour onset, CMMRD is a legitimate differential diagnosis in an otherwise healthy child suspected to have NF1/Legius syndrome without a detectable underlying / germline mutation.

The uptake of presymptomatic genetic testing in hereditary breast-ovarian cancer and Lynch syndrome: a systematic review of the literature and implications for clinical practice.

Following the identification in a proband of a germline BRCA1/BRCA2 mutation in hereditary breast-ovarian cancer (HBOC) or a DNA mismatch repair gene mutation in Lynch syndrome (LS) he or she will be asked to inform at-risk family members about the option for presymptomatic DNA testing. However, in clinical practice multiple factors may complicate the process of information sharing. We critically evaluated studies on the uptake of presymptomatic genetic testing in both syndromes.

How to support cancer genetics counselees in informing at-risk relatives? Lessons from a randomized controlled trial.

Objective: In hereditary and familial cancer, counselees are requested to inform their at-risk relatives. We developed an intervention to support counselees in this task.

Methods: A randomized controlled trial was conducted aimed at improving cancer genetic counselees' i) knowledge, ii) motivation to disclose information, and ii) self-efficacy in this regard.

CDC73-Related Disorders: Clinical Manifestations and Case Detection in Primary Hyperparathyroidism.

Context: Heterozygous pathogenic germline variants in CDC73 predispose to the development of primary hyperparathyroidism (pHPT) and, less frequently, ossifying fibroma of the jaw and renal and uterine tumors. Clinical information on CDC73-related disorders has so far been limited to small case series.

Objective: To assess the clinical manifestations and penetrance in CDC73-related disorders and to improve case detection in pHPT.

Suspected Lynch syndrome associated MSH6 variants: A functional assay to determine their pathogenicity.

Lynch syndrome (LS) is a hereditary cancer predisposition caused by inactivating mutations in DNA mismatch repair (MMR) genes. Mutations in the MSH6 DNA MMR gene account for approximately 18% of LS cases. Many LS-associated sequence variants are nonsense and frameshift mutations that clearly abrogate MMR activity.

Risk of spontaneous pneumothorax due to air travel and diving in patients with Birt-Hogg-Dubé syndrome.

Background And Objectives: Birt-Hogg-Dubé syndrome is an autosomal dominant disorder characterized by skin fibrofolliculomas, lung cysts, spontaneous pneumothorax and renal cell cancer due to germline folliculin (FLCN) mutations (Menko et al. in Lancet Oncol 10(12):1199-1206, 2009). The aim of this study was to evaluate the incidence of spontaneous pneumothorax in patients with BHD during or shortly after air travel and diving.

Design and Feasibility of an Intervention to Support Cancer Genetic Counselees in Informing their At-Risk Relatives.

Cancer genetic counselees receive individualized information regarding heightened risks and medical recommendations which is also relevant for their at-risk relatives. Unfortunately, counselees often insufficiently inform these relatives. We designed an intervention aimed at improving counselees' knowledge regarding which at-risk relatives to inform and what information to disclose, their motivation to disclose, and their self-efficacy.

Diagnosis and Management of Hereditary Renal Cell Cancer.

Renal cell cancer (RCC) is the common denominator for a heterogeneous group of diseases. The subclassification of these tumours is based on histological type and molecular pathogenesis. Insight into molecular pathogenesis has led to the development of targeted systemic therapies.

Hereditary cancer registries improve the care of patients with a genetic predisposition to cancer: contributions from the Dutch Lynch syndrome registry.

The Dutch Hereditary Cancer Registry was established in 1985 with the support of the Ministry of Health (VWS). The aims of the registry are: (1) to promote the identification of families with hereditary cancer, (2) to encourage the participation in surveillance programs of individuals at high risk, (3) to ensure the continuity of lifelong surveillance examinations, and (4) to promote research, in particular the improvement of surveillance protocols. During its early days the registry provided assistance with family investigations and the collection of medical data, and recommended surveillance when a family fulfilled specific diagnostic criteria.

Colorectal cancer risk variants at 8q23.3 and 11q23.1 are associated with disease phenotype in APC mutation carriers.

Familial adenomatous polyposis (FAP) is a dominantly inherited syndrome caused by germline mutations in the APC gene and characterized by the development of multiple colorectal adenomas and a high risk of developing colorectal cancer (CRC). The severity of polyposis is correlated with the site of the APC mutation. However, there is also phenotypic variability within families with the same underlying APC mutation, suggesting that additional factors influence the severity of polyposis.

Are lung cysts in renal cell cancer (RCC) patients an indication for FLCN mutation analysis?

Renal cell cancer (RCC) represents 2-3% of all cancers and is the most lethal of the urologic malignancies, in a minority of cases caused by a genetic predisposition. Birt-Hogg-Dubé syndrome (BHD) is one of the hereditary renal cancer syndromes. As the histological subtype and clinical presentation in BHD are highly variable, this syndrome is easily missed.

Fine mapping of the uterine leiomyoma locus on 1q43 close to a lncRNA in the RGS7-FH interval.

Mutations in fumarate hydratase (FH) on chromosome 1q43 cause a rare cancer syndrome, hereditary leiomyomatosis and renal cell cancer (HLRCC), but are rare in nonsyndromic and common uterine leiomyoma (UL) or fibroids. Studies suggested that variants in FH or in a linked gene may also predispose to UL. We re-sequenced 2.

The effect of genotypes and parent of origin on cancer risk and age of cancer development in PMS2 mutation carriers.

Purpose: Lynch syndrome (LS), a heritable disorder with an increased risk of primarily colorectal cancer (CRC) and endometrial cancer (EC), can be caused by mutations in the PMS2 gene. We wished to establish whether genotype and/or parent-of-origin effects (POE) explain (part of) the reported variability in severity of the phenotype.

Methods: European PMS2 mutation carriers (n = 381) were grouped and compared based on RNA expression and whether the mutation was inherited paternally or maternally.

Low penetrance of paraganglioma and pheochromocytoma in an extended kindred with a germline SDHB exon 3 deletion.

In the Netherlands, the majority of hereditary paragangliomas (PGL) is caused by SDHD, SDHB and SDHAF2 mutations. Founder mutations in SDHD are particularly prevalent, but several SDHB founder mutations have also been described. Here, we describe an extended PGL family with a Dutch founder mutation in SDHB, c.