Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome associated with germline pathogenic/likely pathogenic variants in TP53. Genotype-phenotype correlations are progressively being characterized in LFS with certain TP53 variants associated with attenuated penetrance and phenotypes. We report on a family harboring a TP53 p.R181H variant presenting with a restricted cancer phenotype in adulthood. The proband was a female with breast cancer at the age of 71 years who had three first degree relatives also diagnosed with breast cancer after the age of 40 years (mother, two sisters). Of the nine individuals harboring the variant (6 genetically confirmed, 3 obligate heterozygous), six have not developed malignancies at this time (age range: 36-42). No childhood-onset cancers were reported in this family. A concomitant literature review identified 51 additional individuals harboring the p.R181H variant in TP53, presenting a tumor phenotype dominated by breast cancer. Rare occurrences of other adult-onset cancers (prostate, colorectal and thyroid) and only few childhood onset cancer were documented. These observations are consistent with functional analysis showing that p.R181H retains partial p53 function and suggesting possible reduced cancer penetrance, particularly in the pediatric setting.

Bloom syndrome (BS) is a rare genetic disorder caused by biallelic inactivation of the BLM gene, which usually manifests in childhood by significant growth retardation, immune deficiency, characteristic skin lesions, cancer predisposition and other distinguishable disease features. To our knowledge, all prior instances of BS have been identified via intentional analysis of patients with clinical suspicion for this disease or DNA testing of members of affected pedigrees. We describe an incidental finding of BS, which occurred upon routine germline DNA analysis of consecutive breast cancer patients. The person with the biallelic pathogenic BLM c.1642C>T (p.Gln548Ter) variant remained clinically healthy for 38 years until she developed breast cancer. Detailed examination of this woman, which was carried out after the genetic diagnosis, revealed mild features of BS. A sister chromatid exchange (SCE) test confirmed the presence of this syndrome. The tumor exhibited triple-negative receptor status, a high proliferation rate, a low tumor mutation burden (TMB), and a moderate level of chromosomal instability (homologous recombination deficiency (HRD) score = 29). The patient showed normal tolerability to radiotherapy and several regimens of cytotoxic therapy. Thus, some BS patients may remain undiagnosed due to the mild phenotype of their disease. BLM should be incorporated in gene panels utilized for germline DNA testing of cancer patients.

Germline genomic sequencing is increasingly integrated into pediatric cancer care, with pathogenic cancer-predisposing variants identified among 5-18% of affected children and variants of uncertain significance (VUS) in up to 70%. Given the potential medical implications for children and their families, parents' psychosocial responses to learning results are important to understand. Parents of children with cancer who learned their children's germline pathogenic or VUS results following paired tumor and germline genomic sequencing described their cognitive and affective responses to results in an open-ended write-in question after disclosure (M = 10 months post-disclosure; range = 1-28). Responses were coded and categorized using content analysis, then compared across results using chi-square and Fisher's exact test. Parents of children with pathogenic (n = 9), VUS (n = 52), and pathogenic plus VUS results (n = 9) described negative emotions, positive reactions, mixed emotions (i.e., positive and negative emotions), and neutral reactions. Negative emotions were described significantly more frequently with pathogenic results than VUS only (χ = 5.19; p = .02), with peace of mind and empowerment only described for those with VUS. Parents also described approach(es) to coping (e.g., faith, plan of action) and reactions specific to the uncertainty of VUS (e.g., disappointment at no explanation for cancer etiology). A subset with VUS described decreasing worry/distress with increased understanding of results, whereas others displayed misconceptions regarding VUS. Screening for emotional adjustment is warranted for parents of children with cancer receiving pathogenic germline results, and screening for understanding is warranted with VUS. Findings highlight the importance of pre-and posttest genetic counseling.

To determine the preoperative detection of signet ring cancer cells (SRC) on upper endoscopy (EGD) in patients with CDH1 pathogenic variant (PV) undergoing gastrectomy. To evaluate the development of advanced diffuse gastric cancer (DGC) in patients choosing surveillance. Guidelines recommend prophylactic total gastrectomy (pTG) in CDH1 PV carriers with family history of DGC between 18 and 40 years. Annual EGD with biopsies according to established protocols is recommended in carriers with no SRC and no family history of DGC, with consideration of pTG. Retrospective analysis of asymptomatic patients with CDH1 PVs with ≥ 1 surveillance EGD. Outcomes included pre-operative EGD detection of SRC, surgical stage, and progression to advanced DGC in those electing surveillance with EGD. 48 patients with CDH1 PVs who had ≥ 1 EGD were included. 24/ 48 (50%) underwent gastrectomy, including pTG in 7 patients. SRCC were detected on gastrectomy specimen in 21/24 (87.5%). SRCs were identified by EGD in 17/21 patients who had SRCC on gastrectomy specimens (sensitivity 81%, 17/21). All cancers were stage pT1a. The remaining 17 patients (50% with a family history of gastric cancer) continue in annual EGD surveillance with a median follow-up of 34.6 months. No SRCC or advanced DGC have been diagnosed. No CDH1 PV carriers without SRCC on random biopsies followed in an endoscopic program developed advanced DGC over a median follow up of 3 years. In the short term, EGD surveillance might be a safe alternative to immediate pTG in experienced hands in referral centers.

Biallelic germline pathogenic variants in one of the four mismatch repair genes (MSH2, MSH6, MLH1 and PMS2) cause a very rare, highly penetrant, childhood-onset cancer syndrome, called constitutional mismatch repair deficiency (CMMRD). The European consortium "Care for CMMRD" (C4CMMRD) was founded in Paris in 2013 to facilitate international collaboration and improve our knowledge of this rare cancer predisposition syndrome. Following initial publications on diagnostic criteria and surveillance guidelines for CMMRD, several partners collaborating within the C4CMMRD consortium have worked on and published numerous CMMRD-related clinical and biological projects. Since its formation, the C4CMMRD consortium held meetings every 1-2 years (except in 2020 and 2021 due to the Covid 19 pandemic). The sixth C4CMMRD meeting was held in Paris in November 2022, and brought together 42 participants from nine countries involved in various fields of CMMRD healthcare. The aim was to update members on the latest results and developments from ongoing research, and to discuss and initiate new study proposals. As previously done for the fifth meeting of the C4CMMRD group, this report summarizes data presented at this meeting.

Despite its clinical value, cascade genetic testing (CGT) in hereditary cancer syndromes remains underutilized for a number of reasons, including ineffective family communication of genetic risk information. Therefore, alternative strategies are being explored to improve CGT uptake rates; one such strategy is direct contact with at-risk relatives by healthcare professionals with proband consent. It is unclear how Italian laws and regulations pertaining to CGT-including the EU General Data Protection Regulation (GDPR)-should be understood and implemented in the context of such alternative strategies. The authors constructed a hypothetical case about CGT, reviewed laws and regulations on informed consent, privacy, and the right not to know, and analyzed how those laws and regulations might apply to different communicative strategies relevant to the case and aimed at supporting CGT. A constitutionally consistent reading of Italian law and of the GDPR, an integral part of the Italian privacy framework, suggests that multiple communicative approaches may be legally permissible in Italy to support the CGT process. This includes direct contact by healthcare professionals with proband consent, provided certain conditions are met. Understanding the effectiveness of such approaches in improving CGT uptake will require further research efforts.

Serrated Polyposis Syndrome (SPS) is characterized by multiple and/or large serrated polyps in the colon and an increased risk of colorectal cancer (CRC). The etiology is largely unknown, but in a subset of patients with SPS, monoallelic pathogenic variants in RNF43 are detected. To date, however, the penetrance and phenotypic spectrum of patients carrying pathogenic variants (PV) in RNF43 are poorly described. We present eight patients both with and without serrated polyps from four unrelated families with likely pathogenic variants (LPV) in RNF43 and compare the results to current literature. The patients were referred to genetic counseling due to suspicion of hereditary cancer. They underwent genetic testing with custom NGS gene panels including RNF43 as part of a routine genetic work-up. Three LPVs, one multi-exon deletion and two nonsense variants, were detected in four families. Family I had a history of CRC and serrated polyps, but in the three other families (II‒IV) there was no history of CRC or serrated polyps. Colonoscopies in the probands of these families did not reveal any serrated polyps and/or CRC despite some of them being relatively old. Our findings suggest that the penetrance of RNF43-related disease is much lower than previously thought, and raise questions about the connection between RNF43 and disease. The results highlight the complexity of genetic counseling in RNF43 positive families- particularly in families without polyposis. Further research is needed to elucidate the role of RNF43 in the risk of SPS and CRC.

Lynch syndrome predisposes to a high risk of colorectal cancer and colonoscopy remains the primary preventive strategy. The prevention of colorectal cancer through colonoscopy relies on identifying and removing adenomas, the main precursor lesion. Nevertheless, colonoscopy is not an optimal strategy since post-colonoscopy colorectal cancer remains an important issue. In continuation of a 2021 journal review, the present article seeks to offer an updated perspective by examining relevant articles from the past 3 years. We place recent findings in the context of existing guidelines, with a specific focus on colonoscopy surveillance. Key aspects explored include colonoscopy quality standards, timing of initiation, and surveillance intervals. Our review provides a comprehensive analysis of adenoma-related insights in Lynch syndrome, delving into emerging technologies like virtual chromoendoscopy and artificial intelligence-assisted endoscopy. This review aims to contribute valuable insights into the topic of colonoscopy surveillance in Lynch syndrome.

Colorectal cancer (CRC) is a common cancer in Ireland. Of all CRCs, 2-4% are attributable to Lynch Syndrome (LS), the most common CRC predisposition syndrome. LS is caused by constitutional pathogenic variants (PVs) affecting mismatch repair (MMR) genes with resultant MMR protein deficiency (dMMR). Screening of all CRCs with MMR immunohistochemistry (IHC) testing is advocated to increase the detection of LS. However, successful implementation requires appropriate downstream management. In Ireland the traditional pathway involves referral to cancer genetics services to assess eligibility for genetic testing. Cancer genetics services in Ireland face many challenges in providing uniform access to timely healthcare with current wait times for assessment in excess of 1 year. An increasingly adopted pathway is that of mainstreaming, whereby genetic testing is managed locally by a multidisciplinary team member. Our institution therefore implemented an Advanced Nurse Practitioner (ANP)-led service with responsibility for the LS Diagnostic Pathway and mainstream genetic testing. Data was extracted from a prospectively maintained database of all newly diagnosed CRC patients discussed at our institutions CRC multidisciplinary meeting (MDM) between January 1st, 2023, and May 31st, 2024. MMR IHC testing was performed in 97.9% of the 385 patients diagnosed with CRC. The median time from histological confirmation of CRC to the availability of the MMR IHC report was 6 days. All 51 patients (100%) who required sequential tumor testing underwent BRAF V600 ± MLH1 promoter methylation testing. Additionally, 100% of the 14 patients eligible for mainstream genetic testing were referred to the ANP-led genetics service. The median time from the initial MDM discussion to the initiation of genetic testing was 69 days, while the median time from testing to the availability of results was 19 days. Patients received their results within a median of 21 days. MMR IHC testing increases the detection of LS through identification of dMMR tumours. Successful downstream delivery of clinical services, however, requires appropriate subsequent management, in a resource-limited environment. Our institutional experience demonstrates the feasibility, efficiency, and effectiveness of an ANP-led mainstreaming model of care for hereditary colorectal cancer.

Risk reduction salpingo-oophorectomy (RRSO) is usually performed in women with hereditary breast and ovarian cancer (HBOC) syndrome for BRCA1 and BRCA2 gene mutation carriers, resulting in surgical menopause, which is more associated with a high risk of cardiovascular and metabolic disease than in premenopausal and natural menopausal women. This study assessed the prevalence of cardiovascular and metabolic outcomes in women who underwent salpingo-oophorectomy as a preventive measure against HBOC. This meta-analysis assessed prevalence rates for four metabolic/cardiovascular conditions: myocardial infarction, hypertension, hypercholesterolemia, and type 2 diabetes mellitus. DerSimonian and Laird random-effects models were applied to all analyses, with 95% confidence interval (CI). Heterogeneity was assessed with I². We used OpenMeta Analyst software for statistical analysis. A total of five retrospective studies and one observational study involving 1,320 patients were included. The average body mass index (BMI) was 25.97 kg/m2 and the average waist circumference was 87.94 cm. The analysis across a mean 4.94-year follow-up revealed prevalence rates for acute myocardial infarction of 1.5% (95% CI 0.3-2.7; P = 0.077; I²=56.25%), hypertension of 28% (95% CI 6.9-49.1; P < 0.001; I = 98.42%), hypercholesterolemia of 27.2% (95% CI 6.8-47.6; P < 0.001; I²=98.67%), and type 2 diabetes mellitus of 3.3% (95% CI 1.1-5.5; P < 0.001; I²=82.44%). Our findings suggest that there is no marked increase in cardiovascular risk among women with HBOC undergoing RRSO.

As genetic testing becomes increasingly accessible and affordable, the uniform and accurate interpretation of genetic variants becomes essential. The ACMG/AMP joint guidelines provide the basis for systematic and uniform interpretation of pathogenicity of genetic variants. However, the application of these in routine clinical interpretation at-scale has largely been limited by the lack of resources providing harmonized data especially at a population-scale. Here we describe BRCAIndica, a resource for BRCA1 and BRCA2 variants conforming to the ACMG & AMP joint guidelines to aid uniform clinical interpretation of genetic tests with a specific focus on variants reported in the Indian population. We collected and harmonized variants from across several resources including population-scale datasets, literature survey and other variant datasets. We then classified them according to the ACMG/AMP guidelines.We have collected a total of 10,490 unique variants, of which 2261 Pathogenic and 43 Likely Pathogenic variants belong to BRCA1 and 2694 Pathogenic and 20 Likely Pathogenic variants to BRCA2 respectively. BRCAIndica can be accessed at:https://clingen.igib.res.in/brcaindica/ . In conclusion, BRCAIndica is a powerful resource that offers researchers and clinicians with ACMG/AMP annotated BRCA variants.

Deciphering the spectrum and founder disease-causing variants (DCVs) in specific populations can shape and facilitate the diagnostic process of Lynch Syndrome (LS). The aim of this report was to comprehensively update on the genetic landscape of LS in the ethnically diverse Israeli-Jewish population. The cohort included 1080 carriers from 588 families; some from underrepresented, understudied Israeli ethnic groups recruited from 8 genetic institutes and high-risk clinics throughout the country. Variant classification was performed according to the American College of Medical Genetics criteria. A total of 157 DCVs were identified, 12 are reported here for the first time, and 9 reclassified. MSH2 DCVs were identified in 286 families (49%). Most DCVs (125/157, 80%) were noted in one or two families only. Sixteen DCVs, each detected in ≥ 5 families, and accounted for LS in 378/588 (64%) families. Constitutional mismatch repair deficiency (CMMRD) was diagnosed in 7 families. Twenty-five carriers (2.3%) had an additional DCV or risk alleles in another cancer susceptibility gene. In conclusion, MMR gene variant distribution in Israel is diverse. MSH2 is most commonly mutated due to founder DCVs. Though the 16 prevalent LS-associated DCVs were frequently detected in our cohort, none of them is frequently reported in the general population. These data should facilitate variant interpretation, spouse and cascade testing.

Hereditary cancer predisposition disorders account for up to 10% of all pediatric cancers. Genetic counseling for families of the proband includes risk assessment and recommendations for cascade genetic testing for parents and siblings, but there is no standardized method for cascade testing in place resulting in variability in how clinics approach cascade genetic testing. We explored the uptake and outcomes associated with a family-based approach to cascade testing, for non-syndromic cancer predisposition disorders, at a pediatric cancer genetics clinic serving an ethnically diverse patient population. A retrospective chart review was conducted to evaluate test uptake in the parents and siblings of 106 pediatric probands. The study included 99 mothers, 97 fathers, 116 full siblings, and 53 half siblings who were recommended testing due to genetic risk. Of these relatives, 156 (43%) had documentation of completed cascade testing within twenty-four months after the proband's result disclosure. Completion of cascade testing varied by the type of family member and degree of relatedness. 41% of mothers (41/99) were tested in comparison to 26% of fathers (26/97) and 70.6% of full siblings (82/116) were tested compared to 13.2% of half siblings (7/53). Statistical analysis using chi-squared tests revealed that siblings were more likely to have completed testing than parents (p < 0.001). Furthermore, amongst parents, mothers were more likely to complete testing than fathers (p = 0.03) and amongst siblings, full siblings were more likely to complete testing than half siblings (< 0.001). The proband's age (p = 0.008), parents' preferred language (p = 0.002), and interpreter use during visit (p = 0.004) were the factors associated with differences in test uptake amongst siblings, whereas the proband's race/ethnicity (p = 0.019) was the only factor associated with differences in test uptake amongst parents. The most common barriers noted in charts for lack of test completion included country of residence, lack of insurance, and loss to follow-up. In conclusion, we found that test uptake differed significantly among relatives of a proband with siblings being more likely to test than parents. We also found differences in the demographic and clinical factors associated with test uptake in parents and siblings. Future studies need to validate these differences and further explore the underlying cause of variation in test uptake among relatives.

Non-small cell lung cancer is the most common cause of cancer death globally. When apparent incidental pathogenic germline variants (PGVs) are uncovered with routine next generation sequencing (NGS) of NSCLCs, germline testing (GT) is recommended to confirm that PGV. Because it is far more common that an uncovered tumor TP53 variant is related to a somatic event than an incidental PGV, however, GT for Li Fraumeni syndrome (LFS) is not recommended based solely on uncovering a NSCLC TP53 variant. Because nearly all tumor EGFR variants are also somatic in origin, GT is not recommended based solely on uncovering a tumor EGFR variant.However, there is evidence that patients with coexisting NSCLC variants in both EGFR and TP53 have significant likelihoods of having LFS. For patients with LFS, there are recommended measures for prevention and early detection of LFS-associated cancers and cascade GT of relatives for LFS. Although co-existing genetic variants in NSCLC are not currently used as a biomarker for GT to identify patients with PGVs, given the evidence reviewed here, select patients with NSCLCs that harbor this dual biomarker (i.e., co-existing TP53/EGFR variants) might reasonably be considered for GT for LFS.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal vascular dysplasia characterized by the presence of mucocutaneous telangiectasia and arteriovenous malformations in solid organs. The Curaçao criteria and/or detection of ALK1, ENG, and SMAD4 gene mutations are used for diagnosis. Juvenile Polyposis Syndrome (JPS) is diagnosed according to the number and localization of juvenile polyps, and family history of JPS. Both entities have a low prevalence. Mutation of SMAD4 leads to a combined syndrome of these two conditions called HHT-JPS Overlap Syndrome. We aim to describe the clinical characteristics associated with this condition focusing on long term follow up and review of the literature. A cross-sectional descriptive study of HHT-JPS cases from an HHT Institutional Registry was designed. Patients were eligible for this case series if they fulfilled both HHT and JPS diagnostic criteria and/or mutation on SMAD4. A comprehensive review was conducted on the clinical phenotype associated with HHT and its gastrointestinal involvement. Fourteen patients from eleven families in 788 previously HHT-diagnosed patients met the inclusion criteria. The ages ranged between 25 and 70 years old and 12 were females. In addition to the typical signs/symptoms of HHT, two distinct phenotypes were observed. Nine patients predominantly exhibited initially upper, while five showed predominantly initially lower gastrointestinal involvement. Numerous musculoskeletal and cardiovascular anomalies were also identified. The observed phenotypic diversity, particularly in gastrointestinal involvement, underscores the need for tailored clinical approaches. Comprehensive assessments identified associated musculoskeletal and cardiovascular anomalies, emphasizing the systemic nature of HHT-JPS.

Lynch syndrome (LS) is a hereditary autosomal dominant condition, with an increased lifetime risk of developing malignancies including colorectal cancer (CRC). Current guidelines differ in recommended colonoscopy-surveillance intervals from 1 to 2 years. Although colonoscopy is considered a safe procedure, there are risks of severe adverse events (SAEs), such as perforation and bleeding, as well as adverse events (AEs), such as abdominal discomfort and post-colonoscopy gastrointestinal infections. Colonoscopy-related bleeding and perforation rates have been reported 0.17% and 0.11%, respectively. However, there are insufficient data regarding complications of colonoscopy-surveillance for LS patients. This study aims to investigate the risk of AEs among LS patients during colonoscopy in the Stockholm region.

The discovery of "mismatch repair deficient (MMRd)-crypt foci" in non-neoplastic intestinal mucosa in Lynch syndrome (LS) has significantly enhanced our understanding of how tumors and tumor immunity form and evolve in LS. In this study, we report the frequent presence of "mismatch repair proficient (MMRp)-crypt foci" in both non-neoplastic and neoplastic intestinal mucosa in a patient with constitutional MMR deficiency (CMMRD), who carried a germline MSH6 pathogenic variant (c.3261dupC) in trans with an MSH6 likely pathogenic variant (c.3724_3726del) and whose tissues were otherwise deficient in MMR globally. The MMRp-crypts occurred at a rate of 1.1/100 crypts in non-neoplastic intestinal mucosa and were readily discernible in adenomas > 1 cm. Sequencing analysis revealed normalization of the MSH6c.3261dupC variant in MMRp-adenoma crypts, indicating reverse frameshifting of the exon 5 C8 microsatellite. Interestingly but not surprisingly, the MMRp-adenoma crypts remained microsatellite-instability-high (MSI-H), and shared oncogenic APC mutations with the background MMRd-adenoma. Contrasting with MSH6-CMMRD, no PMS2-CMMRD individuals (0/5) harbored MMRp-crypts. In conclusion, our study documents distinct MMRp-crypts in MSH6-CMMRD, a phenomenon in keeping with MSH6 being a frequent target of MSI-H due to its coding microsatellite and suggesting that MSH6-CMMRD can potentially serve as a unique model system to further our understanding of MSH6's role in MSI-H tumor formation and evolution. Our findings also bear diagnostic implications; when using MMR immunohistochemistry as an ancillary tool in detecting CMMRD, awareness of these MMRp crypts can help avoid diagnostic pitfalls.

Familial adenomatous polyposis (FAP) predisposes individuals to duodenal adenomas. This study describes the histopathological features of endoscopic and surgical specimens from the duodenum, as well as genotype-phenotype associations.

While universal tumor testing for Lynch Syndrome (LS) is recommended in all new diagnoses of colorectal cancer (CC) and endometrial cancer (EC), the cost and availability of this test in low-resource settings poses challenges. The PREdiction Model for gene Mutations (PREMM) is a clinical algorithm designed to assess the risk of an individual carrying estimates one's risk of carrying a LS mutation. This study aims to assess the feasibility of using PREMM to screen for LS risk in Guatemala. This cross-sectional pilot study enrolled 50 patients with colorectal or endometrial cancer receiving treatment at LIGA-INCAN, a cancer hospital in Guatemala City, between June 2022-July 2022. Patients were contacted by phone and administered the PREMM survey, followed by an additional feasibility questionnaire. Of the 50 participants, 62% of patients had a PREMM predicted probability of ≥ 2.5%, the threshold above which genetic testing is recommended. Almost all patients found the survey easy to complete (98%), were able to easily recall personal (90%) and family (88%) medical history, understood its purpose (94%), and reported an interest in (96%) and ability to (98%) act on the results if applicable. Our study shows the role of the PREMM as a feasible tool for identifying individuals at risk of carrying mutations associated with LS in this low-resource setting. By implementing the PREMM model, high risk individuals can be identified early, enabling timely interventions and improving outcomes in this at-risk population.

In the Emilia-Romagna region (Northern Italy), the identification and management of women at familial/hereditary risk of breast and ovarian cancer is guided by a well-established regional protocol. Here we report the results of the experience of private supplementation of public healthcare service in offering the possibility to undergo BRCA1/2 testing and/or multigene panel testing (MGPT) within a well-defined pathway to women unfulfilling regional criteria. Out of 177 patients referred to our center who underwent BRCA1/2 testing, 175 tested negative while two (1.1%) resulted carriers of pathogenic variants in BRCA2; 69 patients also underwent MGPT, and in four cases (5.8%) a pathogenic variant were found (two in ATM and one in CHEK2 and RAD51C, respectively). Overall, this private supplementation of territorial public healthcare system has made it possible to confirm the validity of regional criteria for genetic testing access (concordance: 98.9%), but also to identify carriers of pathogenic variants of BRCA1/2 that would have escaped regional protocol, to support the effectiveness of MGPT for the identification of rare cases (not BRCA) at mild/high risk, and to provide reassurance to women who were found to be non-carriers of pathogenic variants, who may benefit from a more accurate assessment of their risk.