A Collaborative Effort to Define Classification Criteria for ATM Variants in Hereditary Cancer Patients

Abstract Background Gene panel testing by massive parallel sequencing has increased the diagnostic yield but also the number of variants of uncertain significance. Clinical interpretation of genomic data requires expertise for each gene and disease. Heterozygous ATM pathogenic variants increase the risk of cancer, particularly breast cancer. For this reason, ATM is included in most hereditary cancer panels. It is a large gene, showing a high number of variants, most of them of uncertain significance. Hence, we initiated a collaborative effort to improve and standardize variant classification for the ATM gene. Methods Six independent laboratories collected information from 766 ATM variant carriers harboring 283 different variants. Data were submitted in a consensus template form, variant nomenclature and clinical information were curated, and monthly team conferences were established to review and adapt American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) criteria to ATM, which were used to classify 50 representative variants. Results Amid 283 different variants, 99 appeared more than once, 35 had differences in classification among laboratories. Refinement of ACMG/AMP criteria to ATM involved specification for twenty-one criteria and adjustment of strength for fourteen others. Afterwards, 50 variants carried by 254 index cases were classified with the established framework resulting in a consensus classification for all of them and a reduction in the number of variants of uncertain significance from 58% to 42%. Conclusions Our results highlight the relevance of data sharing and data curation by multidisciplinary experts to achieve improved variant classification that will eventually improve clinical management.

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Multi gene panel testing for hereditary breast cancer - is it ready to be used?

Medicine and Pharmacy Reports ◽

10.15386/mpr-1083 ◽

2019 ◽

Cited By ~ 1

Author(s):

Andreea Catana ◽

Adina Patricia Apostu ◽

Razvan-Geo Antemie

Keyword(s):

Breast Cancer ◽

Hereditary Breast Cancer ◽

Gene Panel ◽

Variants Of Uncertain Significance ◽

Panel Testing ◽

Brca Genes ◽

Prophylactic Measures ◽

Gene Panel Testing ◽

Uncertain Significance ◽

High Level

Breast cancer is one of the most common malignancies and the leading cause of death among women worldwide. About 20% of breast cancers are hereditary. Approximately 30% of the mutations have remained negative after testing BRCA1/2 even in families with a Mendelian inheritance pattern for breast cancer. Additional non-BRCA genes have been identified as predisposing for breast cancer. Multi gene panel testing tries to cover and explain the BRCA negative inherited breast cancer, improving efficiency, speed and costs of the breast cancer screening. We identified 23 studies reporting results from individuals who have undergone multi gene panel testing for hereditary breast cancer and noticed a prevalence of 1-12% of non-BRCA genes, but also a high level of variants of uncertain significance. A result with a high level of variants of uncertain significance is likely to be more costly than bring benefits, as well as increase the anxiety for patients. Regarding further development of multi gene panel testing, more research is required to establish both the optimal care of patients with cancer (specific treatments like PARP inhibitors) and the management of unaffected individuals (chemoprevention and/or prophylactic surgeries). Early detection in these patients as well as prophylactic measures will significantly increase the chance of survival. Therefore, multi gene panel testing is not yet ready to be used outside clear guidelines. In conclusion, studies on additional cohorts will be needed to better define the real prevalence, penetrance and the variants of these genes, as well as to describe clear evidence-based guidelines for these patients.

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Universal Multi Gene Panel Testing For Individuals With Pheochromocytomas And Paragangliomas

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.1048 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A512-A513

Author(s):

Carolyn Horton ◽

Marcy Richardson ◽

Kate Durda ◽

Amal Yussuf ◽

Michelle Jackson ◽

...

Keyword(s):

Practice Guidelines ◽

Diagnostic Yield ◽

Positive Family History ◽

Clinical Information ◽

Substantial Contribution ◽

Clinical Predictors ◽

Diagnostic Laboratory ◽

Variant Of Uncertain Significance ◽

Panel Testing ◽

Gene Panel Testing

Abstract Background: Pheochromocytomas (PCCs) and paragangliomas (PGLs) (PPGLs) are a genetically heterogeneous entity, with roughly 25-40% of cases found to harbor a pathogenic or likely pathogenic germline alteration. Existing practice guidelines advocating for the use of a sequential gene testing strategy to identify individuals with hereditary PPGL are driven by the presence of specific clinical features and predate the routine use of multigene panel testing (MGPT). Here we describe results of MGPT for hereditary PPGL in a clinically and ancestrally diverse cohort from a diagnostic laboratory. Methods: Demographic and clinical information of individuals undergoing targeted MGPT for hereditary PPGL were collected from test requisition forms and supporting clinical documents provided by the ordering clinician and retrospectively reviewed. Individuals underwent MGPT of 10-12 genes depending on test order date. From August 2013 through May 2015, 560 individuals had targeted MGPT that included 10 genes (NF1, MAX, SDHA/B/C/D/AF2, RET, TMEM127, and VHL), and from May 2015 through December 2019, 1167 individuals had panel testing of 12 genes due to the addition of MEN1 and FH. Results: Overall, 27.5% of individuals had a pathogenic or likely pathogenic variant (PV), 9.0% had a variant of uncertain significance, and 63.1% had a negative result. Out of all PVs, most were identified in SDHB (40.4%), followed by SDHD (21.1%), SDHA (10.1%), VHL (7.8%), SDHC (6.7%), RET (3.8%), and MAX (3.6%). PVs in FH, MEN1, NF1, SDHAF2, and TMEM127 collectively accounted for 6.5% of PVs. Clinical predictors of a PV included extra-adrenal location, diagnosis before the age of 45 years, multiple tumors, and positive family history (fhx) of PPGL. Affected individuals with a fhx of PPGL were the most likely to have a PV (70.6% of individuals with PCC + fhx; 85.9% of individuals with PGL + fhx). The positive rate in nearly all clinical subgroups even without predictors of a PV remained over 10%, including individuals with a single tumor (PCC = 16.7%; PGL = 46.7%) and those without a fhx (PCC and negative fhx = 15.8%; PGL and negative fhx = 43.7%). Restricting genetic testing of hereditary PPGL to only SDHB/C/D genes misses a third (31.8%) of individuals with PVs. Among individuals with PVs in syndromic genes, over half (41.5%) did not have any additional syndromic features beyond PPGL reported by the ordering clinician. Conclusion: Our data demonstrate a high diagnostic yield in individuals with and without established risk factors, a low inconclusive result rate, numerous individuals with syndromic PVs presenting with isolated PPGL, and a substantial contribution to diagnostic yield from rare genes when included in testing. These findings support updating practice guidelines to incorporate universal testing of all individuals with PPGL and the use of concurrent MGPT as the ideal platform.

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A Phenotype-Enhanced Variant Classification Framework to Decrease the Burden of Missense Variants of Uncertain Significance in Type 1 Long QT Syndrome

Heart Rhythm ◽

10.1016/j.hrthm.2021.11.017 ◽

2021 ◽

Author(s):

Sahej Bains ◽

Steven M. Dotzler ◽

Christian Krijger ◽

John R. Giudicessi ◽

Dan Ye ◽

...

Keyword(s):

Long Qt Syndrome ◽

Variant Classification ◽

Long Qt ◽

Variants Of Uncertain Significance ◽

Missense Variants ◽

Classification Framework ◽

Uncertain Significance ◽

Qt Syndrome

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Gene-specific artificial intelligence-based variant classification engine: results of a time-capsule experiment

10.21203/rs.2.11834/v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Yaron Einhorn ◽

Moshe Einhorn ◽

Adaia Kamshov ◽

Oron Lev ◽

Amir Trabelsi ◽

...

Keyword(s):

Artificial Intelligence ◽

Clinical Information ◽

Cost Effective ◽

Training Data ◽

Variant Classification ◽

Full Dataset ◽

Blinded Study ◽

Novel Variants ◽

Uncertain Significance ◽

Specific Rule

Abstract Background: Interpretation of genetic variation remains an impediment to cost-effective application of genomics to medicine. An advanced artificial intelligence (AI)-based Variant Classification Engine (aiVCE), rooted in ACMG/AMP guidelines, employs data-driven methods to expedite gene-specific classification (franklin.genoox.com). In this blinded study, the aiVCE’s overall and rule-level performances were evaluated using ClinVar (v. 2018-10) variants with creation dates after 5/01/2017. By removing any prior knowledge of these variants from the aiVCE training data, they were treated as novel variants. Using a ‘Full’ dataset (75,801 variants with ≥1 star) and an ‘Increased-Certainty’ dataset (3,993 variants with ≥2 stars), the aiVCE classified variants as pathogenic (P), likely-pathogenic (LP), uncertain significance (VUS), likely-benign (LB), or benign (B). VUS with sufficient supporting data were subclassified as VUS-leaning benign or VUS-leaning pathogenic. aiVCE results were evaluated to determine concordance with final ClinVar classification and rule-level determinations. Results: The aiVCE demonstrated >97% concordance among Increased-Certainty variants. Concordance was >95% across variant effects (e.g., missense, null, splice region), and was >93.5% for the Full dataset. When assessing the aiVCE’s application of specific ACMG rules, significant differences were observed between ClinVar P/LP and B/LB variants rule-met proportions (all P<0.00001), thus supporting gene-specific rule selections. Evaluation of discordance between the aiVCE and ClinVar uncovered evidences that might have been unavailable to submitting laboratories, highlighting AI utility in variant classification. Conclusions: The aiVCE exhibited robust performance, despite lacking past evidence, in determining whether variants would be categorized as P/LP. Applying latest computational advances to existing guidelines may assist scientists and clinicians interpret variants with limited clinical information and greatly reduce analytical bottlenecks.

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Multigene hereditary cancer panel testing for patients with pancreatic cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.4_suppl.244 ◽

2017 ◽

Vol 35 (4_suppl) ◽

pp. 244-244

Author(s):

Anna K McGill ◽

Sheila R Solomon ◽

Megan L Marshall ◽

Lisa Susswein ◽

Corrine Fillman ◽

...

Keyword(s):

Family History ◽

Hereditary Cancer ◽

Diagnostic Yield ◽

Ductal Adenocarcinoma ◽

Panel Testing ◽

Pathogenic Variants ◽

Gene Panel Testing ◽

History Of ◽

Brca1 Brca2 ◽

Cancer Panel

244 Background: Pancreatic ductal adenocarcinoma (PC) is associated with multiple hereditary cancer syndromes. Genes implicated in hereditary PC include ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2 and PMS2. The advent of multi-gene hereditary cancer panel testing streamlines diagnoses and medical management for clinicians and patients. Our objective was to assess the yield of pathogenic/likely pathogenic variants (PV/LPV) in individuals with PC undergoing panel testing as an initial test at GeneDx. Methods: We retrospectively reviewed panel test results of 605 individuals reporting a personal history of PC. Panel testing evaluated up to 32 genes associated with hereditary cancer. Individuals reporting neuroendocrine pathology or previous BRCA1/BRCA2 testing were excluded. Results: In this cohort, 61 PV/LPV were detected in 57 individuals in the following genes: ATM (17), BRCA2 (14), BRCA1 (5), CDKN2A (5), PALB2 (5), CHEK2 (4), MLH1 (2), MUTYH (2), PMS2 (2), BARD1 (1), FANCC (1), MSH2 (1), RAD51D (1) and TP53 (1), corresponding to a positive yield of 9.4% (57/605). Fifty-one of 61 PV/LPV were detected in genes associated with PC (84%) while 10 PV/LPV (16%) were identified in other genes including BARD1, CHEK2, FANCC, MUTYH, and RAD51D. The diagnostic yield among those reporting a family history of PC (33/294, 11.2%) was not statistically different from those without a reported family history (24/311, 7.7%). However, PV/LPV in ATM were detected more often in individuals reporting a family history of PC compared to those without a family history (4.1% vs. 1.6%, p=0.018). Conclusions: In total, 9.4% of patients with PC tested positive for PV/LPV in 14 different genes by panel testing. Although the majority of PV/LPV were identified in known PC genes, 16% of positive findings occurred in genes not typically associated with PC. ATM was most commonly implicated and more frequently reported in patients reporting family histories of PC. Assessing whether these genes are indeed causally related to PC and/or are possibly associated with other cancer types requires further investigation. Based on our results we conclude multi-gene panel testing may be considered as a first option for patients with PC regardless of their family history.

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Insights into Genetic Susceptibility to Melanoma by Gene Panel Testing: Potential Pathogenic Variants in ACD, ATM, BAP1, and POT1

Cancers ◽

10.3390/cancers12041007 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1007 ◽

Cited By ~ 3

Author(s):

Lorenza Pastorino ◽

Virginia Andreotti ◽

Bruna Dalmasso ◽

Irene Vanni ◽

Giulia Ciccarese ◽

...

Keyword(s):

Rare Variants ◽

Diagnostic Yield ◽

Susceptibility Genes ◽

Gene Panel ◽

Missing Heritability ◽

Panel Testing ◽

Pathogenic Variants ◽

Gene Panel Testing ◽

Novel Variants ◽

Uncertain Significance

The contribution of recently established or candidate susceptibility genes to melanoma missing heritability has yet to be determined. Multigene panel testing could increase diagnostic yield and better define the role of candidate genes. We characterized 273 CDKN2A/ARF and CDK4-negative probands through a custom-designed targeted gene panel that included CDKN2A/ARF, CDK4, ACD, BAP1, MITF, POT1, TERF2IP, ATM, and PALB2. Co-segregation, loss of heterozygosity (LOH)/protein expression analysis, and splicing characterization were performed to improve variant classification. We identified 16 (5.9%) pathogenic and likely pathogenic variants in established high/medium penetrance cutaneous melanoma susceptibility genes (BAP1, POT1, ACD, MITF, and TERF2IP), including two novel variants in BAP1 and 4 in POT1. We also found four deleterious and five likely deleterious variants in ATM (3.3%). Thus, including potentially deleterious variants in ATM increased the diagnostic yield to about 9%. Inclusion of rare variants of uncertain significance would increase the overall detection yield to 14%. At least 10% of melanoma missing heritability may be explained through panel testing in our population. To our knowledge, this is the highest frequency of putative ATM deleterious variants reported in melanoma families, suggesting a possible role in melanoma susceptibility, which needs further investigation.

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Multicenter Prospective Cohort Study of the Diagnostic Yield and Patient Experience of Multiplex Gene Panel Testing For Hereditary Cancer Risk

JCO Precision Oncology ◽

10.1200/po.18.00217 ◽

2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Gregory E. Idos ◽

Allison W. Kurian ◽

Charité Ricker ◽

Duveen Sturgeon ◽

Julie O. Culver ◽

...

Keyword(s):

Response Rate ◽

Diagnostic Yield ◽

Prophylactic Surgery ◽

University Of Southern California ◽

Panel Testing ◽

Pathogenic Variants ◽

Gene Panel Testing ◽

Uncertain Significance ◽

Multicenter Prospective Cohort Study ◽

Multicenter Prospective Cohort

Purpose Multiplex gene panel testing (MGPT) allows for the simultaneous analysis of germline cancer susceptibility genes. This study describes the diagnostic yield and patient experiences of MGPT in diverse populations. Patients and Methods This multicenter, prospective cohort study enrolled participants from three cancer genetics clinics—University of Southern California Norris Comprehensive Cancer Center, Los Angeles County and University of Southern California Medical Center, and Stanford Cancer Institute—who met testing guidelines or had a 2.5% or greater probability of a pathogenic variant (N = 2,000). All patients underwent 25- or 28-gene MGPT and results were compared with differential genetic diagnoses generated by pretest expert clinical assessment. Post-test surveys on distress, uncertainty, and positive experiences were administered at 3 months (69% response rate) and 1 year (57% response rate). Results Of 2,000 participants, 81% were female, 41% were Hispanic, 26% were Spanish speaking only, and 30% completed high school or less education. A total of 242 participants (12%) carried one or more pathogenic variant (positive), 689 (34%) carried one or more variant of uncertain significance (VUS), and 1,069 (53%) carried no pathogenic variants or VUS (negative). More than one third of pathogenic variants (34%) were not included in the differential diagnosis. After testing, few patients (4%) had prophylactic surgery, most (92%) never regretted testing, and most (80%) wanted to know all results, even those of uncertain significance. Positive patients were twice as likely as negative/VUS patients (83% v 41%; P < .001) to encourage their relatives to be tested. Conclusion In a racially/ethnically and socioeconomically diverse cohort, MGPT increased diagnostic yield. More than one third of identified pathogenic variants were not clinically anticipated. Patient regret and prophylactic surgery use were low, and patients appropriately encouraged relatives to be tested for clinically relevant results.

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