RESUMO
Determination of the clinical relevance of rare germline variants of uncertain significance (VUSs) in the BRCA2 cancer predisposition gene remains a challenge as a result of limited availability of data for use in classification models. However, laboratory-based functional data derived from validated functional assays of known sensitivity and specificity may influence the interpretation of VUSs. We evaluated 252 missense VUSs from the BRCA2 DNA-binding domain by using a homology-directed DNA repair (HDR) assay and identified 90 as non-functional and 162 as functional. The functional assay results were integrated with other available data sources into an ACMG/AMP rules-based classification framework used by a hereditary cancer testing laboratory. Of the 186 missense variants observed by the testing laboratory, 154 were classified as VUSs without functional data. However, after applying protein functional data, 86% (132/154) of the VUSs were reclassified as either likely pathogenic/pathogenic (39/132) or likely benign/benign (93/132), which impacted testing results for 1,900 individuals. These results indicate that validated functional assay data can have a substantial impact on VUS classification and associated clinical management for many individuals with inherited alterations in BRCA2.
Assuntos
Proteína BRCA2/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Reparo de DNA por Recombinação/genética , Neoplasias da Mama/patologia , Feminino , Variação Genética/genética , Humanos , Mutação de Sentido Incorreto/genética , Relação Estrutura-AtividadeRESUMO
Germline pathogenic variants in DICER1 predispose individuals to develop a variety of benign and malignant tumors. Accurate variant curation and classification is essential for reliable diagnosis of DICER1-related tumor predisposition and identification of individuals who may benefit from surveillance. Since 2015, most labs have followed the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) sequence variant classification guidelines for DICER1 germline variant curation. However, these general guidelines lack gene-specific nuances and leave room for subjectivity. Consequently, a group of DICER1 experts joined ClinGen to form the DICER1 and miRNA-Processing Genes Variant Curation Expert Panel (VCEP), to create DICER1- specific ACMG/AMP guidelines for germline variant curation. The VCEP followed the FDA-approved ClinGen protocol for adapting and piloting these guidelines. A diverse set of 40 DICER1 variants were selected for piloting, including 14 known Pathogenic/Likely Pathogenic (P/LP) variants, 12 known Benign/Likely Benign (B/LB) variants, and 14 variants classified as variants of uncertain significance (VUS) or with conflicting interpretations in ClinVar. Clinically meaningful classifications (i.e., P, LP, LB, or B) were achieved for 82.5% (33/40) of the pilot variants, with 100% concordance among the known P/LP and known B/LB variants. Half of the VUS or conflicting variants were resolved with four variants classified as LB and three as LP. These results demonstrate that the DICER1-specific guidelines for germline variant curation effectively classify known pathogenic and benign variants while reducing the frequency of uncertain classifications. Individuals and labs curating DICER1 variants should consider adopting this classification framework to encourage consistency and improve objectivity.
Assuntos
Testes Genéticos , Neoplasias , Humanos , Testes Genéticos/métodos , Variação Genética , Genoma Humano , Genômica/métodos , Neoplasias/genética , Células Germinativas , Ribonuclease III/genética , RNA Helicases DEAD-box/genéticaRESUMO
PURPOSE: Variants of uncertain significance (VUS) are a common result of diagnostic genetic testing and can be difficult to manage with potential misinterpretation and downstream costs, including time investment by clinicians. We investigated the rate of VUS reported on diagnostic testing via multi-gene panels (MGPs) and exome and genome sequencing (ES/GS) to measure the magnitude of uncertain results and explore ways to reduce their potentially detrimental impact. METHODS: Rates of inconclusive results due to VUS were collected from over 1.5 million sequencing test results from 19 clinical laboratories in North America from 2020 to 2021. RESULTS: We found a lower rate of inconclusive test results due to VUSs from ES/GS (22.5%) compared with MGPs (32.6%; P < .0001). For MGPs, the rate of inconclusive results correlated with panel size. The use of trios reduced inconclusive rates (18.9% vs 27.6%; P < .0001), whereas the use of GS compared with ES had no impact (22.2% vs 22.6%; P = ns). CONCLUSION: The high rate of VUS observed in diagnostic MGP testing warrants examining current variant reporting practices. We propose several approaches to reduce reported VUS rates, while directing clinician resources toward important VUS follow-up.
Assuntos
Predisposição Genética para Doença , Testes Genéticos , Humanos , Testes Genéticos/métodos , Genômica , Exoma/genética , América do NorteRESUMO
BACKGROUND: The nucleotide binding protein-like (NUBPL) gene was first reported as a cause of mitochondrial complex I deficiency (MIM 613621, 618242) in 2010. To date, only eight patients have been reported with this mitochondrial disorder. Five other patients were recently reported to have NUBPL disease but their clinical picture was different from the first eight patients. Here, we report clinical and genetic findings in five additional patients (four families). METHODS: Whole exome sequencing was used to identify patients with compound heterozygous NUBPL variants. Functional studies included RNA-Seq transcript analyses, missense variant biochemical analyses in a yeast model (Yarrowia lipolytica) and mitochondrial respiration experiments on patient fibroblasts. RESULTS: The previously reported c.815-27T>C branch-site mutation was found in all four families. In prior patients, c.166G>A [p.G56R] was always found in cis with c.815-27T>C, but only two of four families had both variants. The second variant found in trans with c.815-27T>C in each family was: c.311T>C [p.L104P] in three patients, c.693+1G>A in one patient and c.545T>C [p.V182A] in one patient. Complex I function in the yeast model was impacted by p.L104P but not p.V182A. Clinical features include onset of neurological symptoms at 3-18 months, global developmental delay, cerebellar dysfunction (including ataxia, dysarthria, nystagmus and tremor) and spasticity. Brain MRI showed cerebellar atrophy. Mitochondrial function studies on patient fibroblasts showed significantly reduced spare respiratory capacity. CONCLUSION: We report on five new patients with NUBPL disease, adding to the number and phenotypic variability of patients diagnosed worldwide, and review prior reported patients with pathogenic NUBPL variants.
Assuntos
Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Adolescente , Encéfalo/diagnóstico por imagem , Criança , Análise Mutacional de DNA , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Doenças Mitocondriais/diagnóstico por imagem , Doenças Mitocondriais/fisiopatologia , Linhagem , RNA-Seq , Sequenciamento do Exoma , Adulto JovemRESUMO
Next-generation sequencing (NGS) technologies are now established in clinical laboratories as a primary testing modality in genomic medicine. These technologies have reduced the cost of large-scale sequencing by several orders of magnitude. It is now cost-effective to analyze an individual with disease-targeted gene panels, exome sequencing, or genome sequencing to assist in the diagnosis of a wide array of clinical scenarios. While clinical validation and use of NGS in many settings is established, there are continuing challenges as technologies and the associated informatics evolve. To assist clinical laboratories with the validation of NGS methods and platforms, the ongoing monitoring of NGS testing to ensure quality results, and the interpretation and reporting of variants found using these technologies, the American College of Medical Genetics and Genomics (ACMG) has developed the following technical standards.
Assuntos
Genética Médica , Laboratórios , Testes Genéticos , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Estados UnidosRESUMO
BACKGROUND: Pathogenic variants in mismatch repair (MMR) genes (MLH1, MSH2, MSH6 and PMS2) increase risk for Lynch syndrome and related cancers. We quantified tumour characteristics to assess variant pathogenicity for germline MMR genes. METHODS: Among 4740 patients with cancer with microsatellite instability (MSI) and immunohistochemical (IHC) results, we tested MMR pathogenic variant association with MSI/IHC status, and estimated likelihood ratios which we used to compute a tumour characteristic likelihood ratio (TCLR) for each variant. Predictive performance of TCLR in combination with in silico predictors, and a multifactorial variant prediction (MVP) model that included allele frequency, co-occurrence, co-segregation, and clinical and family history information was assessed. RESULTS: Compared with non-carriers, carriers of germline pathogenic/likely pathogenic (P/LP) variants were more likely to have abnormal MSI/IHC status (p<0.0001). Among 150 classified missense variants, 73.3% were accurately predicted with TCLR alone. Models leveraging in silico scores as prior probabilities accurately classified >76.7% variants. Adding TCLR as quantitative evidence in an MVP model (MVP +TCLR Pred) increased the proportion of accurately classified variants from 88.0% (MVP alone) to 98.0% and generated optimal performance statistics among all models tested. Importantly, MVP +TCLR Pred resulted in the high yield of predicted classifications for missense variants of unknown significance (VUS); among 193 VUS, 62.7% were predicted as P/PL or benign/likely benign (B/LB) when assessed according to American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines. CONCLUSION: Our study demonstrates that when used separately or in conjunction with other evidence, tumour characteristics provide evidence for germline MMR missense variant assessment, which may have important implications for genetic testing and clinical management.
Assuntos
Reparo de Erro de Pareamento de DNA , Mutação de Sentido Incorreto , Neoplasias/genética , Neoplasias Colorretais Hereditárias sem Polipose , Simulação por Computador , Proteínas de Ligação a DNA/genética , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Neoplasias/metabolismoRESUMO
BACKGROUND: Surgical defects of the distal nose can pose significant reconstructive challenges. Free cartilage batten graft (FCBG) with secondary intention healing is an underreported yet effective repair option with cosmetically and functionally satisfying outcomes. OBJECTIVE: To share the authors' experience using FCBG with secondary intention healing on multiple nasal subunits, including a detailed evaluation of wound/graft characteristics and design modifications to optimize success with this single-stage approach. METHODS: A retrospective study of 129 patients who underwent FCBG with secondary intention healing after Mohs surgery from 2011 to 2018, using statistical analysis of numerous outcome measures graded independently by 2 fellowship-trained Mohs surgeons. RESULTS: Overall, healed wounds were graded aesthetically as follows: excellent (24%), very good (31%), good (31%), or poor (14%). Excellent/very good outcomes were seen for superficial (p < .001), small-to-medium sized wounds (p < .0001) repaired with cartilage that closely approximated the defect size (p < .05). Consistently optimal outcomes were seen in the 19 repairs involving the alar lobule (mid-ala) alone, graded excellent (47%), very good (32%), and good (21%). A majority of patients (86%) experienced mild to no alar retraction. Although 67% of all patients had some skin surface contour irregularity, only 8% of patients sought dermabrasion. Neither hematoma, infection, ear deformity, chondritis, nor graft desiccation were reported. CONCLUSION: A modified approach to FCBG with secondary intention healing provides a reliable, minimalistic, low-risk reconstructive option for mid-alar defects.
Assuntos
Cartilagem/transplante , Neoplasias Nasais/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estética , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Cirurgia de Mohs , Estudos Retrospectivos , CicatrizaçãoRESUMO
Deletions in the 16.6 kb mitochondrial genome have been implicated in numerous disorders that often display muscular and/or neurological symptoms due to the high-energy demands of these tissues. We describe a catalogue of 4489 putative mitochondrial DNA (mtDNA) deletions, including their frequency and relative read rate, using a combinatorial approach of mitochondria-targeted PCR, next-generation sequencing, bioinformatics, post-hoc filtering, annotation, and validation steps. Our bioinformatics pipeline uses MapSplice, an RNA-seq splice junction detection algorithm, to detect and quantify mtDNA deletion breakpoints rather than mRNA splices. Analyses of 93 samples from postmortem brain and blood found (i) the 4977 bp 'common deletion' was neither the most frequent deletion nor the most abundant; (ii) brain contained significantly more deletions than blood; (iii) many high frequency deletions were previously reported in MitoBreak, suggesting they are present at low levels in metabolically active tissues and are not exclusive to individuals with diagnosed mitochondrial pathologies; (iv) many individual deletions (and cumulative metrics) had significant and positive correlations with age and (v) the highest deletion burdens were observed in major depressive disorder brain, at levels greater than Kearns-Sayre Syndrome muscle. Collectively, these data suggest the Splice-Break pipeline can detect and quantify mtDNA deletions at a high level of resolution.
Assuntos
Biologia Computacional/métodos , DNA Mitocondrial/genética , Transtorno Depressivo Maior/genética , Sítios de Splice de RNA/genética , Análise de Sequência de RNA/métodos , Deleção de Sequência , Algoritmos , Sequência de Bases , Encéfalo/metabolismo , Encéfalo/patologia , Quebras de DNA , DNA Mitocondrial/química , Transtorno Depressivo Maior/sangue , Feminino , Humanos , Masculino , Reação em Cadeia da PolimeraseRESUMO
PURPOSE: Genetic testing of individuals often results in identification of genomic variants of unknown significance (VUS). Multiple lines of evidence are used to help determine the clinical significance of these variants. METHODS: We analyzed ~138,000 individuals tested by multigene panel testing (MGPT). We used logistic regression to predict carrier status based on personal and family history of cancer. This was applied to 4644 tested individuals carrying 2383 BRCA1/2 variants to calculate likelihood ratios informing pathogenicity for each. Heterogeneity tests were performed for specific classes of variants defined by in silico predictions. RESULTS: Twenty-two variants labeled as VUS had odds of >10:1 in favor of pathogenicity. The heterogeneity analysis found that among variants in functional domains that were predicted to be benign by in silico tools, a significantly higher proportion of variants were estimated to be pathogenic than previously indicated; that missense variants outside of functional domains should be considered benign; and that variants predicted to create de novo donor sites were also largely benign. CONCLUSION: The evidence presented here supports the use of personal and family history from MGPT in the classification of VUS and will be integrated into ongoing efforts to provide large-scale multifactorial classification.
Assuntos
Neoplasias da Mama , Neoplasias Ovarianas , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Testes Genéticos , Humanos , Anamnese , Neoplasias Ovarianas/genéticaRESUMO
PURPOSE: Despite the rapid uptake of multigene panel testing (MGPT) for hereditary cancer predisposition, there is limited guidance surrounding indications for testing and genes to include. METHODS: To inform the clinical approach to hereditary cancer MGPT, we comprehensively evaluated 32 cancer predisposition genes by assessing phenotype-specific pathogenic variant (PV) frequencies, cancer risk associations, and performance of genetic testing criteria in a cohort of 165,000 patients referred for MGPT. RESULTS: We identified extensive genetic heterogeneity surrounding predisposition to cancer types commonly referred for germline testing (breast, ovarian, colorectal, uterine/endometrial, pancreatic, and melanoma). PV frequencies were highest among patients with ovarian cancer (13.8%) and lowest among patients with melanoma (8.1%). Fewer than half of PVs identified in patients meeting testing criteria for only BRCA1/2 or only Lynch syndrome occurred in the respective genes (33.1% and 46.2%). In addition, 5.8% of patients with PVs in BRCA1/2 and 26.9% of patients with PVs in Lynch syndrome genes did not meet respective testing criteria. CONCLUSION: Opportunities to improve upon identification of patients at risk for hereditary cancer predisposition include revising BRCA1/2 and Lynch syndrome testing criteria to include additional clinically actionable genes with overlapping phenotypes and relaxing testing criteria for associated cancers.
Assuntos
Predisposição Genética para Doença/genética , Testes Genéticos/métodos , Neoplasias/genética , Adulto , Idoso , Proteína BRCA1/genética , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Estudos de Coortes , Neoplasias Colorretais Hereditárias sem Polipose/genética , Feminino , Genes BRCA1 , Genes BRCA2 , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Neoplasias Ovarianas/genéticaRESUMO
PURPOSE: Clinical laboratories performing exome or genome sequencing (ES/GS) are familiar with the challenges associated with proper consenting for and reporting of medically actionable secondary findings based on recommendations from the American College of Medical Genetics and Genomics (ACMG). Misattributed parentage is another type of unanticipated finding a laboratory may encounter during family-based ES/GS; however, there are currently no professional recommendations related to the proper consenting for and reporting of misattributed parentage encountered during ES/GS. METHODS: We surveyed 10 clinical laboratories offering family-based ES/GS regarding their consent language, discovery, and reporting of misattributed parentage. RESULTS: Many laboratories have already developed their own practices/policies for these issues, which do not necessarily agree with those from other labs. CONCLUSION: There are several other possibilities besides true misattributed parentage that could result in similar laboratory findings, and laboratories often feel they lack sufficient information to make formal conclusions on a report regarding the true genetic relatedness of the submitted samples. However, understanding the genetic relatedness (or lack thereof) of the samples submitted for family-based ES/GS has medical relevance. Therefore, professional recommendations for the appropriate handling of suspected misattributed parentage encountered during ES/GS are needed to help standardize current clinical laboratory practices.
Assuntos
Testes Genéticos/tendências , Genética Médica/tendências , Genômica/tendências , Pais , Serviços de Laboratório Clínico , Exoma/genética , Feminino , Genoma Humano/genética , Humanos , Achados Incidentais , Consentimento Livre e Esclarecido , Masculino , Inquéritos e Questionários , Sequenciamento do Exoma/tendências , Sequenciamento Completo do Genoma/tendênciasRESUMO
Peptide hormone relaxin-2, a member of the insulin family of peptides, plays a key role in hemodynamics and renal function and has shown preclinical efficacy in multiple disease models, including acute heart failure, fibrosis, preeclampsia, and corneal wound healing. Recently, serelaxin, a recombinant version of relaxin-2, has been studied in a large phase 3 clinical trial (RELAX-AHF-2) for acute decompensated heart failure patients with disappointing outcome. The poor in vivo half-life of relaxin-2 may have limited its therapeutic efficacy and long-term cardiovascular benefit. Herein, we have developed a semisynthetic methodology and generated potent, fatty acid-conjugated relaxin analogs with long-acting pharmacokinetic (PK) profile in rodents. The enhanced PK properties translated into improved and long-lasting pharmacodynamic effect in pubic ligament elongation (PLE) studies. The resultant novel relaxin analog, R9-13, represents the first long-acting relaxin-2 analog and could potentially improve the clinical efficacy and outcome for this important peptide hormone. This semisynthetic methodology could also be applied to other cysteine-rich peptides and proteins for half-life extension.
Assuntos
Desenho de Fármacos , Lipídeos/química , Relaxina/química , Relaxina/uso terapêutico , Sequência de Aminoácidos , Animais , Meia-Vida , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/uso terapêutico , Relaxina/farmacocinéticaRESUMO
OBJECTIVE: We explored the germline mutation spectrum and prevalence among 1650 women with breast and uterine cancer (BUC) who underwent multi-gene hereditary cancer panel testing at a single commercial laboratory. METHODS: The combined frequency of mutations in 23 BC and/or UC genes was compared between BUC cases and control groups with (1) no personal cancer history; (2) BC only; and (3) UC only using logistic regression. RESULTS: Fourteen percent (nâ¯=â¯231) of BUC cases tested positive for mutations in BC and/or UC genes and were significantly more likely to test positive than individuals with BC only (Pâ¯<â¯0.001), UC only (Pâ¯<â¯0.01), or unaffected controls (Pâ¯<â¯0.001). Analysis of gene-specific mutation frequencies revealed that MSH6, CHEK2, BRCA1, BRCA2, ATM, PMS2, PALB2 and MSH2 were most frequently mutated among BUC cases. Compared to BC only, BRCA1, MLH1, MSH2, MSH6, PMS2 and PTEN mutations were more frequent among BUC; however, only ATM mutations were more frequent among BUC compared to UC only. All of the more commonly mutated genes have published management guidelines to guide clinical care. Of patients with a single mutation in a gene with established testing criteria (nâ¯=â¯152), only 81.6% met their respective criteria, and 65.8% met criteria for multiple syndromes. CONCLUSIONS: Women with BUC are more likely to carry hereditary cancer gene mutations than women with breast or uterine cancer alone, potentially warranting expanded genetic testing for these women. Most mutations found via multi-gene panel testing in women with BUC have accompanying published management guidelines and significant implications for clinical care.
Assuntos
Neoplasias da Mama/genética , Mutação em Linhagem Germinativa , Neoplasias Uterinas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Predisposição Genética para Doença , Testes Genéticos , Humanos , Pessoa de Meia-IdadeRESUMO
Antidiabetic treatments aiming to reduce body weight are currently gaining increased interest. Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist administered twice daily via s.c. injection, improves glycemic control, often with associated weight reduction. To further improve the therapeutic efficacy of exendin-4, we have developed a novel peptide engineering strategy that incorporates a serum protein binding motif onto a covalent side-chain staple and applied to the peptide to enhance its helicity and, as a consequence, its potency and serum half-life. We demonstrated that one of the resulting peptides, E6, has significantly improved half-life and glucose tolerance in an oral glucose tolerance test in rodents. Chronic treatment of E6 significantly decreased body weight and fasting blood glucose, improved lipid metabolism, and also reduced hepatic steatosis in diet-induced obese mice. Moreover, the high potency of E6 allowed us to administer this peptide using a dissolvable microstructure-based transdermal delivery system. Pharmacokinetic and pharmacodynamic studies in guinea pigs showed that a single 5-min application of a microstructure system containing E6 significantly improved glucose tolerance for 96 h. This delivery strategy may offer an effective and patient-friendly alternative to currently marketed GLP-1 injectables and can likely be extended to other peptide hormones.
Assuntos
Peptídeo 1 Semelhante ao Glucagon/química , Engenharia de Proteínas , Administração Cutânea , Sequência de Aminoácidos , Peso Corporal , Dicroísmo Circular , AMP Cíclico/biossíntese , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Peptídeo 1 Semelhante ao Glucagon/farmacocinética , Teste de Tolerância a Glucose , Células HEK293 , HumanosRESUMO
In its landmark paper about Standards and Guidelines for the Interpretation of Sequence Variants, the American College of Medical Genetics and Genomics (ACMG), and Association for Molecular Pathology (AMP) did not address how to use tumor data when assessing the pathogenicity of germline variants. The Clinical Genome Resource (ClinGen) established a multidisciplinary working group, the Germline/Somatic Variant Subcommittee (GSVS) with this focus. The GSVS implemented a survey to determine current practices of integrating somatic data when classifying germline variants in cancer predisposition genes. The GSVS then reviewed and analyzed available resources of relevant somatic data, and performed integrative germline variant curation exercises. The committee determined that somatic hotspots could be systematically integrated into moderate evidence of pathogenicity (PM1). Tumor RNA sequencing data showing altered splicing may be considered as strong evidence in support of germline pathogenicity (PVS1) and tumor phenotypic features such as mutational signatures be considered supporting evidence of pathogenicity (PP4). However, at present, somatic data such as focal loss of heterozygosity and mutations occurring on the alternative allele are not recommended to be systematically integrated, instead, incorporation of this type of data should take place under the advisement of multidisciplinary cancer center tumor-normal sequencing boards.
Assuntos
Variação Genética/genética , Genoma Humano/genética , Mutação/genética , Alelos , Biologia Computacional , Predisposição Genética para Doença/genética , Testes Genéticos/métodos , Genômica , Mutação em Linhagem Germinativa/genética , HumanosRESUMO
The variant curation guidelines published in 2015 by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) provided the genetics community with a framework to assess variant pathogenicity; however, these rules are not gene specific. Germline pathogenic variants in the CDH1 gene cause hereditary diffuse gastric cancer and lobular breast cancer, a clinically challenging cancer predisposition syndrome that often requires a multidisciplinary team of experts to be properly managed. Given this challenge, the Clinical Genome Resource (ClinGen) Hereditary Cancer Domain prioritized the development of the CDH1 variant curation expert panel (VCEP) to develop and implement rules for CDH1 variant classifications. Here, we describe the CDH1 specifications of the ACMG/AMP guidelines, which were developed and validated after a systematic evaluation of variants obtained from a cohort of clinical laboratory data encompassing â¼827,000 CDH1 sequenced alleles. Comparing previously reported germline variants that were classified using the 2015 ACMG/AMP guidelines to the CDH1 VCEP recommendations resulted in reduced variants of uncertain significance and facilitated resolution of variants with conflicted assertions in ClinVar. The ClinGen CDH1 VCEP recommends the use of these CDH1-specific guidelines for the assessment and classification of variants identified in this clinically actionable gene.
Assuntos
Testes Genéticos/métodos , Genoma Humano/genética , Alelos , Biologia Computacional/métodos , Variação Genética/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação/genética , Análise de Sequência de DNA/métodos , Sociedades Médicas , Estados UnidosRESUMO
A recent analysis using family history weighting and co-observation classification modeling indicated that BRCA1 c.594-2A > C (IVS9-2A > C), previously described to cause exon 10 skipping (a truncating alteration), displays characteristics inconsistent with those of a high risk pathogenic BRCA1 variant. We used large-scale genetic and clinical resources from the ENIGMA, CIMBA and BCAC consortia to assess pathogenicity of c.594-2A > C. The combined odds for causality considering case-control, segregation and breast tumor pathology information was 3.23 × 10-8 Our data indicate that c.594-2A > C is always in cis with c.641A > G. The spliceogenic effect of c.[594-2A > C;641A > G] was characterized using RNA analysis of human samples and splicing minigenes. As expected, c.[594-2A > C; 641A > G] caused exon 10 skipping, albeit not due to c.594-2A > C impairing the acceptor site but rather by c.641A > G modifying exon 10 splicing regulatory element(s). Multiple blood-based RNA assays indicated that the variant allele did not produce detectable levels of full-length transcripts, with a per allele BRCA1 expression profile composed of ≈70-80% truncating transcripts, and ≈20-30% of in-frame Δ9,10 transcripts predicted to encode a BRCA1 protein with tumor suppression function.We confirm that BRCA1c.[594-2A > C;641A > G] should not be considered a high-risk pathogenic variant. Importantly, results from our detailed mRNA analysis suggest that BRCA-associated cancer risk is likely not markedly increased for individuals who carry a truncating variant in BRCA1 exons 9 or 10, or any other BRCA1 allele that permits 20-30% of tumor suppressor function. More generally, our findings highlight the importance of assessing naturally occurring alternative splicing for clinical evaluation of variants in disease-causing genes.
Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Mutação/genética , Neoplasias Ovarianas/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Processamento Alternativo/genética , Neoplasias da Mama/patologia , Análise Mutacional de DNA , Éxons/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Sítios de Splice de RNA/genética , Splicing de RNA/genéticaRESUMO
PURPOSE: Blood/saliva DNA is thought to represent the germ line in genetic cancer-risk assessment. Cases with pathogenic TP53 variants detected by multigene panel testing are often discordant with Li-Fraumeni syndrome, raising concern about misinterpretation of acquired aberrant clonal expansions (ACEs) with TP53 variants as germ-line results. METHODS: Pathogenic TP53 variants with abnormal next-generation sequencing metrics (e.g., decreased ratio (<25%) of mutant to wild-type allele, more than two detected alleles) were selected from a CLIA laboratory testing cohort. Alternate tissues and/or close relatives were tested to distinguish between ACE and germ-line status. Clinical data and Li-Fraumeni syndrome testing criteria were examined. RESULTS: Among 114,630 multigene panel tests and 1,454 TP53 gene-specific analyses, abnormal next-generation sequencing metrics were observed in 20% of 353 TP53-positive results, and ACE was confirmed for 91% of cases with ancillary materials, most of these due to clonal hematopoiesis. Only four met Chompret criteria. Individuals with ACE were older (50 years vs. 33.7; P = 0.02) and were identified more frequently in multigene panel tests (66/285; 23.2%) than in TP53 gene-specific tests (6/68; 8.8%, P = 0.005). CONCLUSION: ACE confounds germ-line diagnosis, may portend hematologic malignancy, and may provoke unwarranted clinical interventions. Ancillary testing to confirm germ-line status should precede Li-Fraumeni syndrome management.
Assuntos
Genes p53/genética , Testes Genéticos/métodos , Predisposição Genética para Doença/genética , Variação Genética/genética , Células Germinativas , Mutação em Linhagem Germinativa/genética , Humanos , Síndrome de Li-Fraumeni/diagnóstico , Mutação/genética , Linhagem , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
In the published version of this paper, some of the columns in the last three rows of Table 3 were mistakenly transposed. The corrected table appears below. In col. 6 of the row for DNMT3A, "S3" was published in the original article. However, in the revised table for the corrigendum, it has been corrected to "S1". In col. 6 of the row for SON, "S3" was published in the original article. However, in the revised table for the corrigendum, it has been corrected to "S2".
RESUMO
PURPOSE: Genetic predisposition to male breast cancer (MBC) is not well understood. The aim of this study was to better define the predisposition genes contributing to MBC and the utility of germline multi-gene panel testing (MGPT) for explaining the etiology of MBCs. METHODS: Clinical histories and molecular results were retrospectively reviewed for 715 MBC patients who underwent MGPT from March 2012 to June 2016. RESULTS: The detection rate of MGPT was 18.1% for patients tested for variants in 16 breast cancer susceptibility genes and with no prior BRCA1/2 testing. BRCA2 and CHEK2 were the most frequently mutated genes (11.0 and 4.1% of patients with no prior BRCA1/2 testing, respectively). Pathogenic variants in BRCA2 [odds ratio (OR) = 13.9; p = 1.92 × 10-16], CHEK2 (OR = 3.7; p = 6.24 × 10-24), and PALB2 (OR = 6.6, p = 0.01) were associated with significantly increased risks of MBC. The average age at diagnosis of MBC was similar for patients with (64 years) and without (62 years) pathogenic variants. CHEK2 1100delC carriers had a significantly lower average age of diagnosis (n = 7; 54 years) than all others with pathogenic variants (p = 0.03). No significant differences were observed between history of additional primary cancers (non-breast) and family history of male breast cancer for patients with and without pathogenic variants. However, patients with pathogenic variants in BRCA2 were more likely to have a history of multiple primary breast cancers. CONCLUSION: These data suggest that all MBC patients regardless of age of diagnosis, history of multiple primary cancers, or family history of MBC should be offered MGPT.