Primary CNS Burkitt Lymphoma Presenting as Sudden Bilateral Blindness in a Patient With Underlying Kabuki Syndrome: A Case Report.

Burkitt lymphoma is an aggressive B-cell non-Hodgkin lymphoma (NHL). Primary CNS lymphoma (PCNSL) is a rare disease, and the subtype of Burkitt lymphoma presenting as a sole CNS lesion is an even rarer diagnosis. Acute sudden blindness is a rare presenting symptom of PCNSL or NHL in general. We present an interesting case of a four-year-old boy with dysmorphic features whose visual examination showed a sudden bilateral loss of vision. There was bilateral eye proptosis and complete ptosis. Extraocular muscles were fixed straight. The pupils were fixed and mid dilated bilaterally and there was grade 3/4 papilledema in both eyes. Neuroimaging showed a mass in the base of the skull, extending to orbits and sinuses. A cervical biopsy of the enlarged lymph nodes was taken and a histopathological diagnosis of Burkitt lymphoma was made. Genetic analysis showed a GNB1 mutation, and the patient was diagnosed with Kabuki syndrome by a pediatrician, based on characteristic dysmorphic features. Treatment with steroids and chemotherapy was initiated.

Identification of Novel Potential Predisposing Variants in Familial Acute Myeloid Leukemia.

BACKGROUND: Myeloid neoplasms, including acute myeloid leukemia, have been traditionally among the less investigated cancer types concerning germline predisposition. Indeed, myeloid neoplasms with germline predisposition are challenging to identify because often display similar clinical and morphological characteristics of sporadic cases and have similar age at diagnosis. However, a misidentifications of familiarity in myeloid neoplasms have a critical impact on clinical management both for the carriers and their relatives. AIMS: We conducted a family segregation study, in order to identify novel cancer predisposing genes in myeloid neoplasms and classify novel identified variants. METHODS AND RESULTS: We performed a thorough genomic analysis using a large custom gene panel (256 genes), the Myelo-Panel, targeted on cancer predisposing genes. In particular, we assessed both germline and somatic variants in four families, each with two siblings, who developed hematological neoplasms: seven acute myeloid leukemia and one Philadelphia-positive chronic myeloid leukemia. In each family, we identified at least one novel potentially predisposing variant, affecting also genes not included in the current European LeukemiaNet guidelines for AML management. Moreover, we suggest reclassification of two germline variants as pathogenic: likely pathogenic p.S21Tfs*139 in CEPBA and VUS p.K392Afs*66 in DDX41. CONCLUSION: We believe that predisposition to hematological neoplasms is still underestimated and particularly difficult to diagnosed. Considering that misidentification of familiarity in myeloid neoplasms have a critical impact on the clinical management both for the carriers and their relatives, our study highlights the importance of revision, in this clinical context, of clinical practices that should include thorough reconstruction of family history and in-depth genetic testing.

Hereditary Colorectal Cancer and Polyposis Syndromes Caused by Variants in Uncommon Genes.

A substantial number of hereditary colorectal cancer (CRC) and colonic polyposis cannot be explained by alteration in confirmed predisposition genes, such as mismatch repair (MMR) genes, APC and MUTYH. Recently, a certain number of potential predisposition genes have been suggested, involving each a small number of cases reported so far. Here, we describe the detection of rare variants in the NTLH1, AXIN2, RNF43, BUB1, and TP53 genes in nine unrelated patients who were suspected for inherited CRC and/or colonic polyposis. Seven of them were classified as pathogenic or likely pathogenic variants (PV/LPV). Clinical manifestations of carriers were largely consistent with reported cases with, nevertheless, distinct characteristics. PV/LPV in these uncommon gene can be responsible for up to 2.7% of inherited CRC or colonic polyposis syndromes. Our findings provide supporting evidence for the role of these genes in cancer predisposition, and contribute to the determination of related cancer spectrum and cancer risk for carriers, allowing for the establishment of appropriate screening strategy and genetic counseling in affected families.

Cowden Syndrome: A Rare Cause of Intestinal Polyposis.

Cowden syndrome (CS) is a rare autosomal dominant genodermatosis disorder. This disease is characterized by the development of several hamartomata lesions in a variety of tissues from all three embryonic layers. The most well-known hamartomata are those of the gastrointestinal system, which represent one of the major criteria for the diagnosis of CS. Yet, the most frequent initial presenting symptom of the disease is thought to be mucocutaneous symptoms such as trichilemmomas, acral keratosis, and oral papilloma. Early diagnosis and management are essential to improving the quality of life for patients with CS as this disorder predisposes them to cancers such as thyroid, breast, gastrointestinal, and endometrial cancers. This report presents a rare case of CS in a Bahraini child who presented with macrocephaly and had numerous intestinal polyposis. Genetic testing using whole exome sequencing confirmed the diagnosis, identifying a pathogenic de novo phosphatase and tensin homolog gene (PTEN) variant (Chr10 NM_000314.8: c.17_18del p.(Lys6Argfs*4)) in a heterozygous state. This variant has been confirmed by Sanger sequencing.

Adenomas from individuals with pathogenic biallelic variants in the MUTYH and NTHL1 genes demonstrate base excision repair tumour mutational signature profiles similar to colorectal cancers, expanding potential diagnostic and variant classification applications.

Background: Colorectal cancers (CRCs) from people with biallelic germline likely pathogenic/pathogenic variants in MUTYH or NTHL1 exhibit specific single base substitution (SBS) mutational signatures, namely combined SBS18 and SBS36 (SBS18+SBS36), and SBS30, respectively. The aim was to determine if adenomas from biallelic cases demonstrated these mutational signatures at diagnostic levels. Methods: Whole-exome sequencing of FFPE tissue and matched blood-derived DNA was performed on 9 adenomas and 15 CRCs from 13 biallelic MUTYH cases, on 7 adenomas and 2 CRCs from 5 biallelic NTHL1 cases and on 27 adenomas and 26 CRCs from 46 non-hereditary (sporadic) participants. All samples were assessed for COSMIC v3.2 SBS mutational signatures. Results: In biallelic MUTYH cases, SBS18+SBS36 signature proportions in adenomas (mean±standard deviation, 65.6%±29.6%) were not significantly different to those observed in CRCs (76.2%±20.5%, p-value=0.37), but were significantly higher compared with non-hereditary adenomas (7.6%±7.0%, p-value=3.4×10-4). Similarly, in biallelic NTHL1 cases, SBS30 signature proportions in adenomas (74.5%±9.4%) were similar to those in CRCs (78.8%±2.4%) but significantly higher compared with non-hereditary adenomas (2.8%±3.6%, p-value=5.1×10-7). Additionally, a compound heterozygote with the c.1187G>A p.(Gly396Asp) pathogenic variant and the c.533G>C p.(Gly178Ala) variant of unknown significance (VUS) in MUTYH demonstrated high levels of SBS18+SBS36 in four adenomas and one CRC, providing evidence for reclassification of the VUS to pathogenic. Conclusions: SBS18+SBS36 and SBS30 were enriched in adenomas at comparable proportions observed in CRCs from biallelic MUTYH and biallelic NTHL1 cases, respectively. Therefore, testing adenomas may improve the identification of biallelic cases and facilitate variant classification, ultimately enabling opportunities for CRC prevention.

Phenotypic spectrum and tumor risk in Simpson-Golabi-Behmel syndrome: Case series and comprehensive literature review.

Simpson-Golabi-Behmel syndrome (SGBS) is a rare congenital overgrowth condition characterized by macrosomia, macroglossia, coarse facial features, and development delays. It is caused by pathogenic variants in the GPC3 gene on chromosome Xq26.2. Here, we performed a comprehensive literature review and phenotyping of known patients with molecularly confirmed SGBS and reviewed a novel cohort of 22 patients. Using these data, we characterized the tumor risk for Wilms tumor and hepatoblastoma to suggest appropriate screening for this patient population. In addition, we discuss the phenotypic overlap between SGBS and Beckwith-Wiedemann Spectrum.

Germline susceptibility from broad genomic profiling of pediatric brain cancers.

Background: Identifying germline predisposition in CNS malignancies is of increasing clinical importance, as it contributes to diagnosis and prognosis, and determines aspects of treatment. The inclusion of germline testing has historically been limited due to challenges surrounding access to genetic counseling, complexity in acquiring a germline comparator specimen, concerns about the impact of findings, or cost considerations. These limitations were further defined by the breadth and scope of clinical testing to precisely identify complex variants as well as concerns regarding the clinical interpretation of variants including those of uncertain significance. Methods: In the course of conducting an IRB-approved protocol that performed genomic, transcriptomic and methylation-based characterization of pediatric CNS malignancies, we cataloged germline predisposition to cancer based on paired exome capture sequencing, coupled with computational analyses to identify variants in known cancer predisposition genes and interpret them relative to established clinical guidelines. Results: In certain cases, these findings refined diagnosis or prognosis or provided important information for treatment planning. Conclusions: We outline our aggregate findings on cancer predisposition within this cohort which identified 16% of individuals (27 of 168) harboring a variant predicting cancer susceptibility and contextualize the impact of these results in terms of treatment-related aspects of precision oncology.

The different faces of GATA2 deficiency: implications for therapy and surveillance.

GATA2 deficiency is one of the most common genetic predispositions to pediatric myelodysplastic syndrome (MDS) in children and adolescents. The wide spectrum of disease comprises, among others, hematological, immunological and pulmonary manifestations, as well as occasionally distinct organ anomalies. Due to the elevated risk of progression, nearly all individuals with GATA2-related MDS eventually undergo a hematopoietic stem cell transplantation (HSCT) at some point in their lives. Nevertheless, the optimal timing, method, and even the indication for HSCT in certain cases are still matter of debate and warrant further research. In this article, we report five patients with different hematological and immunological manifestations of GATA2 deficiency ranging from immunodeficiency and refractory cytopenia of childhood without chromosomal aberrations to relapsed MDS-related acute myeloid leukemia. We discuss the adopted strategies, including intensity of surveillance, indication and timing of HSCT, based on morphological, clinical and molecular markers, as well as individual patient needs. We conclude that a better characterization of the natural disease course, a better understanding of the prognostic significance of somatic aberrations and a thorough evaluation of patients´ perspectives and preferences are required to achieve a personalized approach aimed at improving the care of these patients.

Feasibility of whole-body MRI for cancer screening in children and young people with ataxia telangiectasia: A mixed methods cross-sectional study.

BACKGROUND/OBJECTIVES: Ataxia telangiectasia (A-T) is an inherited multisystem disorder with increased sensitivity to ionising radiation and elevated cancer risk. Although other cancer predisposition syndromes have established cancer screening protocols, evidence-based guidelines for cancer screening in A-T are lacking. This study sought to assess feasibility of a cancer screening protocol based on whole-body MRI (WB-MRI) in children and young people with A-T. DESIGN/METHODS: Children and young people with A-T were invited to undergo a one-off non-sedated 3-Tesla WB-MRI. Completion rate of WB-MRI was recorded and diagnostic image quality assessed by two experienced radiologists, with pre-specified success thresholds for scan completion of >50% participants and image quality between acceptable to excellent in 65% participants. Positive imaging findings were classified according to the ONCO-RADS system. Post-participation interviews were performed with recruited families to assess the experience of participating and feelings about waiting for, and communication of, the findings of the scan. RESULTS: Forty-six children and young people with A-T were identified, of which 36 were eligible to participate, 18 were recruited and 16 underwent WB-MRI. Nineteen parents participated in interviews. Fifteen participants (83%) completed the full WB-MRI scan protocol. The pre-specified image quality criterion was achieved with diagnostic images obtained in at least 93% of each MRI sequence. Non-malignant scan findings were present in 4 (25%) participants. Six themes were identified from the interviews: (1) anxiety is a familiar feeling, (2) the process of MRI scanning is challenging for some children and families, (3) preparation is essential to reduce stress, (4) WB-MRI provides the reassurance about the physical health that families need, (5) WB-MRI experience turned out to be a positive experience and (6) WB-MRI allows families to be proactive. CONCLUSION: This study shows that WB-MRI for cancer screening is feasible and well-accepted by children and young people with A-T and their families.

Medulloblastomas with ELP1 pathogenic variants: A weakly penetrant syndrome with a restricted spectrum in a limited age window.

Background: ELP1 pathogenic variants (PV) have been recently identified as the most frequent variants predisposing to Sonic Hedgehog (SHH) medulloblastomas (MB); however, guidelines are still lacking for genetic counseling in this new syndrome. Methods: We retrospectively reviewed clinical and genetic data of a French series of 29 ELP1-mutated MB. Results: All patients developed SHH-MB, with a biallelic inactivation of PTCH1 found in 24 tumors. Other recurrent alterations encompassed the TP53 pathway and activation of MYCN/MYCL signaling. The median age at diagnosis was 7.3 years (range: 3-14). ELP1-mutated MB behave as sporadic cases, with similar distribution within clinical and molecular risk groups and similar outcomes (5 y - OS = 86%); no unusual side effect of treatments was noticed. Remarkably, a germline ELP1 PV was identified in all patients with available constitutional DNA (n = 26); moreover, all tested familial trio (n = 11) revealed that the PVs were inherited. Two of the 26 index cases from the French series had a family history of MB; pedigrees from these patients and from 1 additional Dutch family suggested a weak penetrance. Apart from MB, no cancer was associated with ELP1 PVs; second tumors reported in 4 patients occurred within the irradiation fields, in the usual time-lapse for expected radiotherapy-induced neoplasms. Conclusions: The low penetrance, the "at risk' age window limited to childhood and the narrow tumor spectrum, question the actual benefit of genetic screening in these patients and their family. Our results suggest restricting ELP1 germline sequencing to patients with SHH-MB, depending on the parents" request.

James German and the Quest to Understand Human RECQ Helicase Deficiencies.

James German's work to establish the natural history and cancer risk associated with Bloom syndrome (BS) has had a strong influence on the generation of scientists and clinicians working to understand other RECQ deficiencies and heritable cancer predisposition syndromes. I summarize work by us and others below, inspired by James German's precedents with BS, to understand and compare BS with the other heritable RECQ deficiency syndromes with a focus on Werner syndrome (WS). What we know, unanswered questions and new opportunities are discussed, as are potential ways to treat or modify WS-associated disease mechanisms and pathways.

Occurrence of cancer in Marfan syndrome: Report of two patients with neuroblastoma and review of the literature.

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by pathogenic variants in FBN1, with a hitherto unknown association with cancer. Here, we present two females with MFS who developed pediatric neuroblastoma. Patient 1 presented with neonatal MFS and developed an adrenal neuroblastoma with unfavorable tumor genetics at 10 months of age. Whole genome sequencing revealed a germline de novo missense FBN1 variant (NP_000129.3:p.(Asp1322Asn)), resulting in intron 32 inclusion and exon 32 retention. Patient 2 was diagnosed with classic MFS, caused by a germline de novo frameshift variant in FBN1 (NP_000129.3:p.(Cys805Ter)). At 18 years, she developed high-risk neuroblastoma with a somatic ALK pathogenic variant (NP_004295.2:p.(Arg1275Gln)). We identified 32 reported cases of MFS with cancer in PubMed, yet none with neuroblastoma. Among patients, we observed an early cancer onset and high frequency of MFS complications. We also queried cancer databases for somatic FBN1 variants, finding 49 alterations reported in PeCan, and variants in 2% of patients in cBioPortal. In conclusion, we report the first two patients with MFS and neuroblastoma and highlight an early age at cancer diagnosis in reported patients with MFS. Further epidemiological and functional studies are needed to clarify the growing evidence linking MFS and cancer.

BUB1B monoallelic germline variants contribute to prostate cancer predisposition by triggering chromosomal instability.

BACKGROUND: Prostate cancer (PrCa) is the most frequently diagnosed cancer in men. Variants in known moderate- to high-penetrance genes explain less than 5% of the cases arising at early-onset (< 56 years) and/or with familial aggregation of the disease. Considering that BubR1 is an essential component of the mitotic spindle assembly checkpoint, we hypothesized that monoallelic BUB1B variants could be sufficient to fuel chromosomal instability (CIN), potentially triggering (prostate) carcinogenesis. METHODS: To unveil BUB1B as a new PrCa predisposing gene, we performed targeted next-generation sequencing in germline DNA from 462 early-onset/familial PrCa patients and 1,416 cancer patients fulfilling criteria for genetic testing for other hereditary cancer syndromes. To explore the pan-cancer role of BUB1B, we used in silico BubR1 molecular modeling, in vitro gene-editing, and ex vivo patients' tumors and peripheral blood lymphocytes. RESULTS: Rare BUB1B variants were found in ~ 1.9% of the early-onset/familial PrCa cases and in ~ 0.6% of other cancer patients fulfilling criteria for hereditary disease. We further show that BUB1B variants lead to decreased BubR1 expression and/or stability, which promotes increased premature chromatid separation and, consequently, triggers CIN, driving resistance to Taxol-based therapies. CONCLUSIONS: Our study shows that different BUB1B variants may uncover a trigger for CIN-driven carcinogenesis, supporting the role of BUB1B as a (pan)-cancer predisposing gene with potential impact on genetic counseling and treatment decision-making.

Germline pathogenic variants of cancer predisposition genes in a multicentre Italian cohort of pancreatic cancer patients.

BACKGROUND AND AIM: Germline BRCA1-2 test is routinely recommended in Pancreatic Cancer (PC) patients, due to its clinical-epidemiological relevance. Data on the prevalence of germline pathogenic variants (gPV) in other cancer predisposition and DNA Damage Repair (DDR) system-related genes in unselected PC cases are sparce in Italy. We assessed this prevalence in a multicentre cohort, to derive recommendations for PC patients. METHODS: Clinical data of 1200 consecutive PC patients, of any age and stage, tested with a multigene germline panel were collected. A descriptive analysis of gPV frequency and clinical variables was performed both in 1092 patients tested for an 18 genes core-panel (CP-18 cohort) and in 869 patients screened only for CDKN2A. RESULTS: 11.5 % (126/1092) of CP-18 cohort patients harbored a gPV in ≥ 1 gene. Highest gPV frequencies were detected in ATM (3.1 %), BRCA2 (2.9 %), BRCA1 (1.6 %), CHEK2 (1.1 %). Patients harboring any CP-18 gene and BRCA1-2 gPV were younger and with a higher rate of personal (PH) or family history (FH) of cancer when compared to no gPV patients. The risk of having a gPV was ≥ 7 % in all subgroups of patients, including those aged > 73, with tumor stage I-III and negative FH/PH. CDKN2A gPV were detected in 2.6 % (23/869) of patients. CONCLUSIONS: A remarkable prevalence of gPV in cancer predisposition and DDR genes is reported in this large multicentre cohort of consecutive and unselected PC patients. Therefore, we recommend multigene germline testing (at least including BRCA1-2, ATM, CDKN2A, PALB2) for all PC patients, irrespective of age, stage, PH/FH.

Genomic Newborn Screening for Pediatric Cancer Predisposition Syndromes: A Holistic Approach.

As next-generation sequencing (NGS) has become more widely used, germline and rare genetic variations responsible for inherited illnesses, including cancer predisposition syndromes (CPSs) that account for up to 10% of childhood malignancies, have been found. The CPSs are a group of germline genetic disorders that have been identified as risk factors for pediatric cancer development. Excluding a few "classic" CPSs, there is no agreement regarding when and how to conduct germline genetic diagnostic studies in children with cancer due to the constant evolution of knowledge in NGS technologies. Various clinical screening tools have been suggested to aid in the identification of individuals who are at greater risk, using diverse strategies and with varied outcomes. We present here an overview of the primary clinical and molecular characteristics of various CPSs and summarize the existing clinical genomics data on the prevalence of CPSs in pediatric cancer patients. Additionally, we discuss several ethical issues, challenges, limitations, cost-effectiveness, and integration of genomic newborn screening for CPSs into a healthcare system. Furthermore, we assess the effectiveness of commonly utilized decision-support tools in identifying patients who may benefit from genetic counseling and/or direct genetic testing. This investigation highlights a tailored and systematic approach utilizing medical newborn screening tools such as the genome sequencing of high-risk newborns for CPSs, which could be a practical and cost-effective strategy in pediatric cancer care.

Parents' and patients' perspectives, experiences, and preferences for germline genetic or genomic testing of children with cancer: A systematic review.

PURPOSE: Germline testing in pediatric cancer presents opportunities and challenges. Understanding family perspectives, experiences, and preferences will optimize integration into routine care. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched 4 databases for studies exploring perspectives, experiences, and preferences of parents/caregivers and/or patients regarding germline testing of children with cancer. Qualitative and quantitative data were extracted, organized, and summarized by research question and themes. RESULTS: We identified 2286 unique articles, of which 24 were included. Interest in and uptake of testing was high. Families were motivated by altruism and a desire for inheritance/causation information. Testing barriers included psychological concerns, timing of the testing approach if offered at diagnosis or in a high-risk cancer setting and privacy/discrimination. Testing experiences highlighted challenges yet also positive impacts, with results providing psychological relief and informing proactive decision making. Timing preferences varied; however, allowing time to adjust to a new diagnosis was a common theme. Most wanted to receive as many germline sequencing-related results as possible. CONCLUSION: Findings underscore the importance of integrating germline analyses into pediatric cancer care with flexibility and support for families facing challenges. Where possible, consent should be provided at a time that suits each family's situation with access to information aligning with their needs and preferences. PROSPERO: CRD42023444890.

Therapeutic applications of germline testing for cancer predisposition genes in Asia in the real world.

BACKGROUND: Germline genetic testing is traditionally carried out in patients suspected with hereditary cancer syndrome for enhanced cancer surveillance and/or preventive strategies, but is increasingly carried out for therapeutic indications. MATERIALS AND METHODS: We conducted a retrospective review of patients who underwent germline genetic testing at our centre to determine the prevalence of actionable pathogenic germline variants (PGV) and their clinical utility. RESULTS: From 2000 to 2022, 1154 cancer patients underwent germline testing, with the majority (945/1154) tested with multi-gene panels. Four hundred and eleven (35.6%) patients harboured a PGV and 334 (81%) were clinically actionable. BRCA1/2 accounted for 62.3% of actionable mutations, followed by mismatch repair (18%), and other homologous recombination repair (HRR) genes (19.7%). One hundred and fifty-two germline-positive patients have advanced cancers, and 79 received germline-directed therapies (poly ADP ribose polymerase inhibitors = 75; immunotherapy = 4). Median duration of immunotherapy and poly ADP ribose polymerase were 20.5 months (range 5-40 months) and 8 months (range 1-76 months), respectively. Among BRCA/HRR mutation carriers who received platinum-based chemotherapy, pathological complete response rate in the neoadjuvant setting was 53% (n = 17 breast cancers) and objective response rate was >80% in the advanced setting (n = 71). CONCLUSIONS: One-third of cancer patients tested carried a PGV and ∼80% were clinically actionable. Three-quarters of germline-positive advanced cancer patients received germline-directed therapies in the real world, underscoring the practical utility of germline testing to guide cancer therapeutics.

An Inherited Allele Confers Prostate Cancer Progression and Drug Resistance via RFX6/HOXA10-Orchestrated TGFß Signaling.

Genetic and epigenetic alterations are cancer hallmark characteristics. However, the role of inherited cancer predisposition alleles in co-opting lineage factor epigenetic reprogramming and tumor progression remains elusive. Here the FinnGen cohort phenome-wide analysis, along with multiple genome-wide association studies, has consistently identified the rs339331-RFX6/6q22 locus associated with prostate cancer (PCa) risk across diverse populations. It is uncovered that rs339331 resides in a reprogrammed androgen receptor (AR) binding site in PCa tumors, with the T risk allele enhancing AR chromatin occupancy. RFX6, an AR-regulated gene linked to rs339331, exhibits synergistic prognostic value for PCa recurrence and metastasis. This comprehensive in vitro and in vivo studies demonstrate the oncogenic functions of RFX6 in promoting PCa cell proliferation and metastasis. Mechanistically, RFX6 upregulates HOXA10 that profoundly correlates with adverse PCa outcomes and is pivotal in RFX6-mediated PCa progression, facilitating the epithelial-mesenchymal transition (EMT) and modulating the TGFß/SMAD signaling axis. Clinically, HOXA10 elevation is associated with increased EMT scores, tumor advancement and PCa recurrence. Remarkably, reducing RFX6 expression restores enzalutamide sensitivity in resistant PCa cells and tumors. This findings reveal a complex interplay of genetic and epigenetic mechanisms in PCa pathogenesis and drug resistance, centered around disrupted prostate lineage AR signaling and abnormal RFX6 expression.

A second hereditary cancer predisposition syndrome in a patient with lynch syndrome and three primary cancers.

Current National Comprehensive Cancer Network ® (NCCN ®) guidelines for Colorectal Genetic/Familial High-Risk Assessment provide limited guidance for genetic testing for individuals with already diagnosed hereditary cancer conditions. We are presenting the case of a 36-year-old woman who was diagnosed with Lynch Syndrome at age 23 after genetic testing for a familial variant (c.283del) in the MLH1 gene. The patient had a previous history of Hodgkin Lymphoma at the time of familial variant testing, and she would later develop stage IIIa cecal adenocarcinoma at age 33 and metastatic papillary thyroid carcinoma at age 35. The patient's family history included a first-degree relative who was diagnosed with colorectal cancer at age 39, multiple second-degree relatives with colorectal, endometrial, and stomach cancer, and third and fourth-degree relatives with breast cancer. In light of her personal and family history, a comprehensive cancer panel was recommended. This panel found a second hereditary cancer predisposition syndrome: a likely pathogenic variant (c. 349 A > G) in the CHEK2 gene. This specific CHEK2 variant was recently reported to confer a moderately increased risk for breast cancer. The discovery of this second cancer predisposition syndrome had important implications for the patient's screening and risk management. While uncommon, the possibility of an individual having multiple cancer predisposition syndromes is important to consider when evaluating patients and families for hereditary cancer, even when a familial variant has been identified.

Parallel DNA/RNA NGS Using an Identical Target Enrichment Panel in the Analysis of Hereditary Cancer Predisposition.

Germline DNA testing using the next-gene-ration sequencing (NGS) technology has become the analytical standard for the diagnostics of hereditary diseases, including cancer. Its increasing use places high demands on correct sample identification, independent confirmation of prioritized variants, and their functional and clinical interpretation. To streamline these processes, we introduced parallel DNA and RNA capture-based NGS using identical capture panel CZECANCA, which is routinely used for DNA analysis of hereditary cancer predisposition. Here, we present the analytical workflow for RNA sample processing and its analytical and diagnostic performance. Parallel DNA/RNA analysis allowed credible sample identification by calculating the kinship coefficient. The RNA capture-based approach enriched transcriptional targets for the majority of clinically relevant cancer predisposition genes to a degree that allowed analysis of the effect of identified DNA variants on mRNA processing. By comparing the panel and whole-exome RNA enrichment, we demonstrated that the tissue-specific gene expression pattern is independent of the capture panel. Moreover, technical replicates confirmed high reproducibility of the tested RNA analysis. We concluded that parallel DNA/RNA NGS using the identical gene panel is a robust and cost-effective diagnostic strategy. In our setting, it allows routine analysis of 48 DNA/RNA pairs using NextSeq 500/550 Mid Output Kit v2.5 (150 cycles) in a single run with sufficient coverage to analyse 226 cancer predisposition and candidate ge-nes. This approach can replace laborious Sanger confirmatory sequencing, increase testing turnaround, reduce analysis costs, and improve interpretation of the impact of variants by analysing their effect on mRNA processing.