DNA-based screening and population health: a points to consider statement for programs and sponsoring organizations from the American College of Medical Genetics and Genomics (ACMG)

Abstract

A comment to this article is available online at https://doi.org/10.1038/s41436-021-01141-w. Screening is an organized application of a test or inquiry to identify individuals at sufficient risk of a specific disorder to benefit from either further evaluation or direct preventive action.1.Wald N.J. The definition of screening.1:STN:280:DC%2BD3M3ptFCnsQ%3D%3D10.1136/jms.8.1.1J. Med. Screen. 2001; 8: 1Google Scholar DNA-based screening, that is, the identification of DNA variants in unselected individuals to predict latent disease risk, constitutes a new approach for health screening. The use of DNA-based health screening to guide preventive care in the screened individual has long been discussed, but until recently has had limited applications.2.Gilbert W. DNA sequencing, today and tomorrow.1:STN:280:DyaK38%2FhtF2kug%3D%3D10.1080/21548331.1991.11705313Hosp. Pract. (Off. Ed.). 1991; 26: 165-169, 172, 174Google Scholar Screening is distinct from indication-driven DNA testing, referred to as diagnostic testing. DNA technologies now make primary screening applications possible in a wide range of settings. Beyond institutional review board (IRB)-approved research, any screening application for DNA-based risk detection should be evidence-based and adherent to the health screening criteria established by Wilson and Jungner more than 50 years ago.3.Wilson J.M. Jungner Y.G. Principles and practice of mass screening for disease.1:STN:280:DyaF1M%2FhsVWquw%3D%3D4234760Bol. Oficina Sanit. Panam. 1968; 65: 281-393Google Scholar The American College of Medical Genetics and Genomics (ACMG) has generated this document with seven points to consider (Table 1) to guide programs and sponsoring organizations that are considering DNA-based health screening. Individuals who are undergoing DNA-based screening and their health-care providers are encouraged to review the ACMG statement on DNA-based screening and personal health for additional points to consider.4.Bean, L. et al. DNA-based screening and personal health: a points to consider statement for individuals and healthcare providers from the American College of Medical Genetics and Genomics (ACMG). Genet. Med. (in press).Google Scholar In aggregate, DNA-based screening efforts have the potential to improve population health, but only if risk identification is effectively combined with evidence-based risk-reducing clinical care.Table 1Seven points to consider from the American College of Medical Genetics and Genomics (ACMG).DNA-based screening and population health points to consider1The ACMG secondary findings recommendations do not constitute a primary health screening recommendation or strategy.2DNA-based screening should not replace a standard-of-care evaluation for individuals with a clinical indication for diagnostic assessment.3Disease risks identified through screening should not include DNA variants of uncertain significance (VUS).4DNA-based screening should be linked to opportunities for evidence-based risk-reducing clinical care.5Risk-reducing clinical follow-up for DNA-based screening should be consistent with best practices outlined by professional societies with appropriate expertise.6Organizations involved in DNA-based screening are expected to participate in sharing of outcomes-related data.7DNA-based screening applications with proven beneficial clinical outcomes should be made available to entire populations to promote health-care equity and limit health disparities. Open table in a new tab This document will focus on issues related to implementation strategies for DNA-based screening, which requires distinguishing “screening” from the use of DNA-based “diagnostic testing” that has been applied within health care for decades. When DNA-based testing is pursued as part of a diagnostic effort, the individual who is undergoing the testing has already been identified as having an increased pretest probability of a positive genetic test based on signs, symptoms, physical exam, other diagnostic tests or family history (Fig. 1a). ACMG secondary findings recommendations are limited to the review of existing exome or genome sequencing data that was generated as part of the diagnostic process.5.Green R.C. et al.ACMG recommendations for reporting of incidental findings in clinical exome and genome sequencing.1:CAS:528:DC%2BC3sXhtVKku73K10.1038/gim.2013.73Genet. Med. 2013; 15: 565-574Google Scholar, 6.Kalia S.S. et al.Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics.10.1038/gim.2016.190Genet. Med. 2017; 19: 249-255Google Scholar, 7.ACMG Board of Directors The use of ACMG secondary findings recommendations for general population screening: a policy statement of the American College of Medical Genetics and Genomics (ACMG).10.1038/s41436-019-0502-5Genet. Med. 2019; 21: 1467-1468Google Scholar In contrast, the goal of DNA-based screening is to introduce testing within an unselected population to identify persons without prior suspicion of genetic risk for disease development (Fig. 1b, c). There are longstanding principles that guide health screening. Ten enduring criteria were outlined by Wilson and Jungner in their 1968 treatise.3.Wilson J.M. Jungner Y.G. Principles and practice of mass screening for disease.1:STN:280:DyaF1M%2FhsVWquw%3D%3D4234760Bol. Oficina Sanit. Panam. 1968; 65: 281-393Google Scholar For the purposes of this document, these original criteria are displayed alongside a version of the criteria tailored for a DNA-based screening and population health context (Table 2). To date, evidence of fulfillment of these ten criteria have not been unambiguously demonstrated for any DNA-based health screening application for adults.Table 2Wilson and Jungner criteria in the context of DNA-based screening and population health.Wilson and Jungner criteriaCriteria in DNA-based screening and population health context1The condition sought should be an important health problem.Screening should focus on the identification of genomic risk(s) for important health problems.2There should be an accepted treatment for patients with recognized disease.Options for evidence-based clinical actions should be communicated to patients in whom the genomic risk is identified.3Facilities for diagnosis and treatment should be available.Clinical implementation strategies should be in place and available to anyone identified as having genomic risk.4There should be a recognizable latent or early symptomatic stage.Screening should have the capability of identifying at-risk individuals during both presymptomatic and early symptomatic disease stages.5There should be a suitable test or examination.The DNA-based strategy should constitute an improvement over existing strategies for risk identification and risk reduction.6The test should be acceptable to the population.Proven screening applications should be available to all but individual participation should be optional.7The natural history of the condition, including development from latent to declared disease, should be adequately understood.Anticipated penetrance and expressivity (i.e., natural history) should be understood based on data from comparable populations.8There should be an agreed policy on whom to treat as patients.Consensus should exist on clinical classification and management for those patients who screen positive for genomic risk but in whom the evidence of the associated health problems is absent (i.e., nonpenetrant risk).9The cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole.Appropriate health economic analyses should be in place to understand programmatic costs and benefits.10Case-finding should be a continuing process and not a “once and for all” project.There should exist plans for both:- Periodic reanalysis of DNA variants using updated information.- Periodic clinical re-evaluation of individuals with nonpenetrant risk. Open table in a new tab The genes associated with “tier 1 genomic applications” are widely considered a core list for consideration in the context of screening.8.Khoury M.J. et al.A collaborative translational research framework for evaluating and implementing the appropriate use of human genome sequencing to improve health.10.1371/journal.pmed.1002631PLoS Med. 2018; 15: e1002631Google Scholar These applications are defined by the Centers for Disease Control and Prevention (CDC)’s Office of Public Health Genomics (OPHG) as those having significant potential for positive impact on public health based on available evidence-based guidelines and recommendations.8.Khoury M.J. et al.A collaborative translational research framework for evaluating and implementing the appropriate use of human genome sequencing to improve health.10.1371/journal.pmed.1002631PLoS Med. 2018; 15: e1002631Google Scholar The genomic conditions are hereditary breast and ovarian cancer (HBOC), Lynch syndrome (LS), and familial hypercholesterolemia (FH). The three tier 1 genomic conditions are specifically associated with risk for breast, ovarian, colon, and endometrial cancers, coronary artery disease, and stroke and are therefore consistent with Wilson and Jungner’s guidance to focus health screening on “important health problems” (Table 3).3.Wilson J.M. Jungner Y.G. Principles and practice of mass screening for disease.1:STN:280:DyaF1M%2FhsVWquw%3D%3D4234760Bol. Oficina Sanit. Panam. 1968; 65: 281-393Google Scholar,8.Khoury M.J. et al.A collaborative translational research framework for evaluating and implementing the appropriate use of human genome sequencing to improve health.10.1371/journal.pmed.1002631PLoS Med. 2018; 15: e1002631Google Scholar The three genomic conditions on this consensus list are associated with nine genes that are also included in the list of ACMG secondary finding recommendations.5.Green R.C. et al.ACMG recommendations for reporting of incidental findings in clinical exome and genome sequencing.1:CAS:528:DC%2BC3sXhtVKku73K10.1038/gim.2013.73Genet. Med. 2013; 15: 565-574Google Scholar,6.Kalia S.S. et al.Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics.10.1038/gim.2016.190Genet. Med. 2017; 19: 249-255Google ScholarTable 3Ten frequently cited gene–condition pairs for DNA-based screening and population health.Gene(s)ConditionClinGen actionability score32.Hunter J.E. et al.A standardized, evidence-based protocol to assess clinical actionability of genetic disorders associated with genomic variation.1:CAS:528:DC%2BC28XitVegtL3F10.1038/gim.2016.40Genet. Med. 2016; 18: 1258-1268Google ScholarMajor disease riskFollow-up (secondary) test or procedure (per guidelines)Goal of follow-up test or procedureEstimated penetrance in screened populationsEstimated penetrance in cohorts ascertained based on personal and familial diseaseBRCA1Hereditary breast and ovarian cancer syndrome (HBOC)8–10Breast cancerBreast imaging and prophylactic surgeryIdentify existing disease at early stageNot establishedF: 46–87%33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarM: 1.2%33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarOvarian cancerProphylactic surgeryReduce cancer riskNot establishedF: 39–63%33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarNDProstate cancerRoutine screeningIdentify existing disease at early stageNot establishedM: 8.6% (by 65 years old)33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarBRCA2Hereditary breast and ovarian cancer syndrome (HBOC)8–10Breast cancerBreast imaging and prophylactic surgeryIdentify existing disease at early stageNot establishedF: 38–84%33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarM: up to 8.9%33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarOvarian cancerProphylactic surgeryReduce cancer riskNot establishedF: 16.5–27%33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarNDProstate cancerRoutine screeningIdentify existing disease at early stageNot establishedM: 15% (by 65 years old)33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarM: 20% (lifetime)33.Petrucelli, N., Daly, M. B. & Pal, T. in GeneReviews (eds Adam, M. P. et al.) BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. (University of Washington, Seattle, 2016).Google ScholarMLH1 MSH2Lynch syndrome (LS)10Colorectal cancer (CRC)ColonoscopyIdentify precursor lesions and existing disease at early stageNot establishedF: 22–53%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google ScholarM: 27–74%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google Scholar8–9Endometrial cancerSurveillance and prophylactic surgeryIdentify existing disease at early stageNot establishedF: 14–54%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google ScholarMSH6Lynch syndrome (LS)10Colorectal cancer (CRC)ColonoscopyIdentify precursor lesions and existing disease at early stageNot establishedF: 10%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google ScholarM: 22%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google Scholar8–9Endometrial cancerSurveillance and prophylactic surgeryIdentify existing disease at early stageNot establishedF: 16–26%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google ScholarPMS2Lynch syndrome (LS)10Colorectal cancer (CRC)ColonoscopyIdentify precursor lesions and existing disease at early stageNot establishedF: 15%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google ScholarM: 20%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google Scholar8–9Endometrial cancerSurveillance and prophylactic surgeryIdentify existing disease at early stageNot establishedF: 15%34.Kohlmann, W. & Gruber, S. B. in GeneReviews (eds Adam, M. P. et al.) Lynch syndrome. (University of Washington, Seattle, 2018).Google ScholarEPCAMLynch syndrome (LS)10Colorectal cancer (CRC)ColonoscopyIdentify precursor lesions and existing disease at early stageNot establishedNot established8–9Endometrial cancerSurveillance and prophylactic surgeryIdentify existing disease at early stageNot establishedNot establishedLDLRFamilial hypercholesterolemia (FH)11Coronary artery disease (CAD)Serum LDL cholesterolGuide therapeutic interventionsNot establishedNot establishedStrokeSerum LDL cholesterolGuide therapeutic interventionsNot establishedNot establishedAPOBFamilial hypercholesterolemia (FH)11Coronary artery disease (CAD)Serum LDL cholesterolGuide therapeutic interventionsNot establishedNot establishedStrokeSerum LDL cholesterolGuide therapeutic interventionsNot establishedNot establishedPCSK9Familial hypercholesterolemia (FH)11Coronary artery disease (CAD)Serum LDL cholesterolGuide therapeutic interventionsNot establishedNot establishedStrokeSerum LDL cholesterolGuide therapeutic interventionsNot establishedNot established Open table in a new tab A key data gap in our efforts to demonstrate the fulfillment of the health screening criteria for DNA-based screening is our incomplete understanding of what Wilson and Jungner referred to as the “natural history of the condition.” Natural history in this context involves penetrance; the proportion of individuals with a given genomic risk who show evidence of the associated clinical problems; expressivity, the range of clinical manifestations associated with a specific genomic risk; and age of onset. While we have a detailed understanding of the tier 1 conditions in the context of cohorts identified through diagnostic testing, the natural history data are far more limited for cohorts identified through DNA-based screening approaches (Table 3). Estimates of population penetrance for BRCA1/2 have been published, and these were developed using four interdependent epidemiologic parameters: (1) the probability of developing breast cancer, (2) the proportion of breast cancer cases with a BRCA1 or BRCA2 pathogenic variant, (3) the proportion of women that carries a pathogenic variant, and (4) the proportion of women with a pathogenic variant that develops cancer.9.McClain M.R. Palomaki G.E. Nathanson K.L. Haddow J.E. Adjusting the estimated proportion of breast cancer cases associated with BRCA1 and BRCA2 mutations: public health implications.1:CAS:528:DC%2BD2MXkvFWgug%3D%3D10.1097/01.GIM.0000151155.36470.FFGenet. Med. 2005; 7: 28-33Google Scholar This approach will prove useful for organizations who desire to make estimates for BRCA1/2 or other monogenic risks. It is important to emphasize that a positive result in DNA-based screening is not equivalent to a diagnosis of the “health problem” of interest.10.Murray M.F. Your DNA is not your diagnosis: getting diagnoses right following secondary genomic findings.1:CAS:528:DC%2BC28XhtlejtbzL10.1038/gim.2015.134Genet. Med. 2016; 18: 765-767Google Scholar,11.Biesecker L.G. Nussbaum R.L. Rehm H.L. Distinguishing variant pathogenicity from genetic diagnosis: how to know whether a variant causes a condition.10.1001/jama.2018.14900JAMA. 2018; 320: 1929-1930Google Scholar DNA-based risk identification in the absence of relevant medical history places individuals in a category for which we do not have sufficient consensus on clinical classification and management (Table 2). For example, a patient with a pathogenic MLH1 variant but without relevant family history or clinical evidence of colon or other associated cancers has nonpenetrant “disease risk” but not LS. Health-care systems, insurers, providers, and patients need better language to describe someone who has a DNA-based risk identified and needs ongoing surveillance (Fig. 1c), but does not have, and may never develop, penetrant disease. Simply listing the positive genetic test result in the problem list of the electronic health record to prompt appropriate ongoing follow-up without labeling a patient as having a “diagnosis” has been proposed.12.Schwartz M.L.B. et al.A model for genome-first care: returning secondary genomic findings to participants and their healthcare providers in a large research cohort.1:CAS:528:DC%2BC1cXhsVOlu7bI10.1016/j.ajhg.2018.07.009Am. J. Hum. Genet. 2018; 103: 328-337Google Scholar Further study is needed to develop a best practice solution. Our understanding of the range of clinical problems associated with any genetic risk is mostly based on our understanding from cases ascertained through diagnostic testing. As screening becomes more routine, an appreciation of an extended range of clinical problems, particularly on the mild end of the spectrum, is likely to be elucidated. An example of this improved understanding of expressivity has occurred with cystic fibrosis where proactive screening for disease has helped to clarify the association of bilateral absence of the vas deferens and CFTR-related metabolic syndrome.13.Levy H. Farrell P.M. New challenges in the diagnosis and management of cystic fibrosis.10.1016/j.jpeds.2015.03.042J. Pediatr. 2015; 166: 1337-1341Google Scholar The natural history of a condition includes an age of onset for the relevant diseases in question. More research will be required to understand both the median age and the age range for diseases attributed to the risks ascertained through this type of DNA-based screening. Clearer understanding of age of onset will allow for more strategic decision making about the optimal age for the initial DNA screen and the optimal ages for the follow-up preventive measures. The ACMG published recommendations for reporting of secondary findings in clinical exome and genome sequencing in 2013 and updated those recommendations in 2016.5.Green R.C. et al.ACMG recommendations for reporting of incidental findings in clinical exome and genome sequencing.1:CAS:528:DC%2BC3sXhtVKku73K10.1038/gim.2013.73Genet. Med. 2013; 15: 565-574Google Scholar,6.Kalia S.S. et al.Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics.10.1038/gim.2016.190Genet. Med. 2017; 19: 249-255Google Scholar In these efforts the ACMG has produced a list of 59 genes and 30 conditions to help guide secondary analysis of genomic data generated as part of diagnostic care.6.Kalia S.S. et al.Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics.10.1038/gim.2016.190Genet. Med. 2017; 19: 249-255Google Scholar This list emphasizes the medical actionability of existing data as the motivation for uncovering secondary findings. The ACMG Secondary Finding Maintenance Working Group’s 2016 statement summarized their approach as including five major criteria for medical actionability: (1) severity of disease/nature of the health threat, (2) likelihood of the disease/health threat materializing (i.e., penetrance), (3) efficacy of specific intervention(s), (4) overall strength of the current knowledge base about the gene/condition, and (5) acceptability of the proposed intervention based on its risks and benefits. They also noted that the last criterion was highly personal and subjective. Efforts to formalize a more quantitative approach to clinical actionability have been furthered within the ClinGen project, and we have incorporated output from that standardized ClinGen Actionability Scale 0–12 into this document (Table 3).14.Hunter J.E. et al.A standardized, evidence-based protocol to assess clinical actionability of genetic disorders associated with genomic variation.1:CAS:528:DC%2BC28XitVegtL3F10.1038/gim.2016.40Genet. Med. 2016; 18: 1258-1268Google Scholar Actionability is a key concept used in the selection of gene–condition pairs for both secondary findings (identified within existing data generated in a diagnostic effort) as well as new data generated proactively through screening. An overlap of genes and conditions for these different applications is to be expected, and as the evidence base is built to effectively prevent disease, there may be a more complete overlap. Currently, however, proactive efforts to screen for disease risk through DNA analysis is distinct from secondary findings and should be grounded in the same long-established principles as other health screening. This grounding includes extending attention beyond individual risk identification and risk-reducing clinical care to include broader societal concepts, such as health services delivery and economics. The health service delivery options for DNA-based health screening are currently in flux.4.Bean, L. et al. DNA-based screening and personal health: a points to consider statement for individuals and healthcare providers from the American College of Medical Genetics and Genomics (ACMG). Genet. Med. (in press).Google Scholar,15.Hagenkord J. et al.Design and reporting considerations for genetic screening tests.1:CAS:528:DC%2BB3cXlsFalur0%3D10.1016/j.jmoldx.2020.01.014J. Mol. Diagn. 2020; 22: 599-609Google Scholar The economic concept articulated by Wilson and Jungner (Table 2) is “the cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole.”3.Wilson J.M. Jungner Y.G. Principles and practice of mass screening for disease.1:STN:280:DyaF1M%2FhsVWquw%3D%3D4234760Bol. Oficina Sanit. Panam. 1968; 65: 281-393Google Scholar Much of the health services and economic research needed to address the DNA-based screening issues are yet to be done. Individuals with signs, symptoms, or family history should be assessed for the potential need for DNA-based diagnostic testing (Fig. 1a), and such individuals would be ill-served by a limited DNA-based screening approach. The issues raised by signs, symptoms, and family history should be handled as part of appropriate clinical care by medical professionals. A woman with a strong family history of breast cancer who undergoes a limited DNA-based screening approach, such as a few common pathogenic BRCA1 and BRCA2 variants, can provide an instructive example of the potential harms of substituting DNA-based screening for a diagnostic assessment. While this screening, if positive, may give sufficient diagnostic information and thereby end the DNA-based evaluation, if negative it could offer false reassurance and truncate a more complete evaluation. The more complete DNA-based diagnostic evaluation would potentially include a review of a larger panel of genes, more complete analysis of known variants including higher resolution copy-number analysis, detection of other known structural variants as well as strategies to address difficult to sequence regions (e.g., PMS2 for Lynch syndrome), a more comprehensive variant evaluation to include variants of uncertain clinical significance (VUS), or potential follow-up of VUS to include segregation studies within the family. The more complete clinical follow-up would potentially include familial breast cancer–based risk assessment and recommendations for risk-reducing clinical care in the absence of identifying a pathogenic DNA variant. We acknowledge that the potential exists for a multistage evaluation process for a person in need of a diagnostic assessment. Wherein, a positive DNA-based screening result completes the genetic evaluation but a negative screening result triggers a second stage of testing and evaluation. However, an effective use of this type of multistaged approach has not been demonstrated. Standards and guidelines for the interpretation of sequence variants were set forth by the ACMG and the Association for Molecular Pathology in 2015.16.Richards S. et al.Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.10.1038/gim.2015.30Genet. Med. 2015; 17: 405-424Google Scholar There are five categories of variant interpretation under this standard, and resulting of diagnostic tests typically returns three of those categories, namely pathogenic (P), likely pathogenic (LP), and VUS. The two remaining categories are benign (B) and likely benign (LB). It is important to note that these interpretation categories are reflective of the state of the evidence within the field of clinical genomics at a given point in time. Programs involved in DNA-based screening need to operate with the expectation that within any established workflow, the list of reportable variants will change with time. For instance, at any specific point in time the discrete set of variants that prompt reporting to participants will likely differ from the set that will prompt reporting 12 months later due to the evolving evidence base. The evolving evidence sets up a need in every ongoing program to periodically review the data against an updated standard data set. This review could reveal that the interpretation for one of the participant’s previously identified DNA variants has moved closer to or further from pathogenic. Workflows should be established within programs to proactively identify changes in variant categories. Follow-up reporting of any significant revision should be communicated to the patient and their provider so that appropriate clinical follow-up can be pursued. In a DNA-based screening approach, only P and LP should be reported in order to drive risk-reducing clinical care.16.Richards S. et al.Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.10.1038/gim.2015.30Genet. Med. 2015; 17: 405-424Google Scholar There is some debate about whether LP should be included in screening because over time it may not reliably be reclassified to P. Recent analyses have demonstrated that a majority of LP reclassifications from ClinVar (2016 to 2019) were LP to P.17.Harrison S.M. Rehm H.L. Is ‘likely pathogenic’ really 90% likely? Reclassification data in ClinVar.10.1186/s13073-019-0688-9Genome Med. 2019; 11Google Scholar It is important however for organizations and providers engaged in DNA-based screening to understand the potential for reclassification of variants (upgraded or downgraded), and to address this in any screening approach by communicating this potential reclassification to individuals receiving disease risk information.4.Bean, L. et al. DNA-based screening and personal health: a points to consider statement for individuals and healthcare providers from the American College of Medical Genetics and Genomics (ACMG). Genet. Med. (in press).Google Scholar There is, however, strong consensus that the category of VUS, which by definition is composed of those variants with insufficient information to interpret,16.Richards S. et al.Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.10.1038/gim.2015.30Genet. Med. 2015; 17: 405-424Google Scholar should be excluded from DNA-based screening results. VUS are one of the motivating factors in the need for periodic reanalysis of DNA variants using new information including population database updates and updates to variant classification recommendations (Table 2). With time many VUS will become interpretable and a small subset of those will potentially drive risk-reducing clinical care. The Wilson and Jungner criteria call for the availability of facilities for diagnosis and treatment following health screening.3.Wilson J.M. Jungner Y.G. Principles and practice of mass screening for disease.1:STN:280:DyaF1M%2FhsVWquw%3D%3D4234760Bol. Oficina Sanit. Panam. 1968; 65: 281-393Google Scholar In the context of DNA-based screening, clearly articulated clinical implementation strategies need to be in place and available to anyone identified as having genomic risk in this manner (see Table 2), since identification of DNA-based risk without opportunities for risk-reducing clinical care would result in missed opportunities to improve health.18.Vrečar I. Hristovski D. Peterlin B. Telegenetics: an update on availability and use of telemedicine in clinical genetics service.10.1007/s10916-016-0666-3J. Med. Syst. 2017; 41Google Scholar, 19.Penon-Portmann M. Chang J. Cheng M. Shieh J.T. Genetics workforce: distribution of genetics services and challenges to health care in California.10.1038/s41436-019-0628-5Genet. Med. 2020; 22: 227-231Google Scholar, 20.Institute of Medicine (US) Roundtable on Translating Genomic-Based Research for Health. The Value of Genetic and Genomic Technologies: Workshop Summary. (National Academies Press, Washington, DC, 2010).Google Scholar Clinical practice guidelines exist for the diagnosis and management of many genomic conditions, including HBOC, LS, and FH.21.National Comprehensive Cancer Network. Genetic/familial high-risk assessment: breast, ovarian, and pancreatic. https://www.nccn.org/professionals/physician_gls/pdf/genetics_bop.pdf (2020).Google Scholar, 22.National Comprehensive Cancer Network. Genetic/familial high-risk assessment: colorectal. https://www.nccn.org/professionals/physician_gls/pdf/genetics_colon.pdf (2020).Google Scholar, 23.Goldberg A.C. et al.Familial hypercholesterolemia: screening, diagnosis and management of pediatric and adult patients: clinical guidance from the National Lipid Association Expert Panel on Familial Hypercholesterolemia.10.1016/j.jacl.2011.04.003J. Clin. Lipidol. 2011; 5: S1-S8Google Scholar These guidelines are based on evidence from cases typically ascertained through diagnostic (Fig. 1a) rather than screening approaches (Fig. 1b, c). For cases ascertained through DNA-based screening, the existing diagnosis and management recommendations have clear value but may, with time, need to be modified for this mode of case ascertainment. As data regarding penetrance and expressivity from DNA-screened cohorts accrue, recommendations for the management of individuals with risk identified via screening may require a distinct set of guidelines due to the expected reduced penetrance. Clinical practice guidelines should be based on best available evidence at the time of testing. Registries that standardize and aggregate data could foster evidence-based updates to management recommendations. Organizations and providers offering DNA-based screening need to implement or facilitate the implementation of existing guidelines for the individuals who screen positive for risk variants and evaluate both health and implementation outcomes to foster continuous quality improvement. If the goal of improving population health through DNA-based screening is to be achieved, then the aggregation of outcomes data from many screened individuals is essential.24.ACMG Board of Directors Laboratory and clinical genomic data sharing is crucial to improving genetic health care: a position statement of the American College of Medical Genetics and Genomics.1:CAS:528:DC%2BC2sXhtFygsLfL10.1038/gim.2016.196Genet. Med. 2017; 19: 721-722Google Scholar All organizations, both public and private, should share de-identified outcomes data, including P and LP variants and their frequencies, health outcomes of risk-reducing clinical care, and clinical outcomes related to penetrance and expressivity. To aid in the aggregation and analysis of outcomes, definitions should be harmonized and broadly disseminated.25.Peterson J.F. Roden D.M. Orlando L.A. Ramirez A.H. Mensah G.A. Williams M.S. Building evidence and measuring clinical outcomes for genomic medicine.1:CAS:528:DC%2BC1MXhsFertrbK10.1016/S0140-6736(19)31278-4Lancet. 2019; 394: 604-610Google Scholar,26.Williams J.L. et al.Harmonizing outcomes for genomic medicine: comparison of eMERGE outcomes to ClinGen outcome/intervention pairs.10.3390/healthcare6030083Healthcare (Basel). 2018; 6: 83Google Scholar Since these efforts are aimed at contributing to the greater good, outcome sharing should not be limited to health-care organizations. Shared databases optimized for screening may need to be created. Currently, deposition of data in public databases (such as ClinVar) and peer-reviewed publication are among the existing avenues that can be used for sharing aimed at improving efforts to prevent disease. There are persistent racial, ethnic, and socioeconomic disparities in health care and health status.27.Centers for Disease Control and Prevention (CDC Conclusion and future directions: CDC Health Disparities and Inequalities Report – United States, 2013.24264513MMWR Suppl. 2013; 62: 184-186Google Scholar The concern has been raised that genomic testing has the potential to increase health disparities.28.West K.M. Blacksher E. Burke W. Genomics, health disparities, and missed opportunities for the nation’s research agenda.10.1001/jama.2017.3096JAMA. 2017; 317: 1831-1832Google Scholar The National Academy of Medicine sponsored a 2018 workshop that focused on understanding inequities in access to genomic medicine including social and language barriers, training of health-care providers, the limited genomics workforce, patient awareness, and privacy and potential discrimination related to insurance coverage.29.National Academies of Sciences, Engineering, and Medicine. Understanding Disparities in Access to Genomic Medicine: Proceedings of a Workshop. (The National Academies Press, Washington, DC, 2018).Google Scholar Given that inequities and disparities exist, and genomic medicine may exacerbate these differences, the ACMG supports efforts to make DNA-based screening applications that are shown to improve population health available to everyone. Namely, once a use-case is demonstrated to improve population health through DNA-based risk identification combined with risk-reducing clinical care, it should be made readily available to everyone based on appropriate data.30.Manrai A.K. et al.Genetic misdiagnoses and the potential for health disparities.10.1056/NEJMsa1507092N. Engl. J. Med. 2016; 375: 655-665Google Scholar The routine population-wide offering of newborn screening (NBS) through collaborations between state departments of public health and health-care delivery systems demonstrates the type of collaborative efforts that can achieve this goal. In the near term, organizations that are carrying out DNA-based screening should seek inclusiveness across racial, ethnic, and socioeconomic groups, so that evidence for improved health outcomes, as well as an infrastructure that supports population-wide screening applications, are being built in parallel. If DNA-based screening is to improve population health, then it must be combined with effective risk-reducing clinical care. This will be a continual process, or as Wilson and Jungner framed it, not a “once and for all” project (Table 2). Evolving management guidelines that are implemented will require (1) periodic reanalysis of DNA variants informed by updated databases (e.g., ClinVar), (2) periodic clinical re-evaluation of disease status in at-risk individuals, and (3) periodic assessment of the effectiveness of strategies that support implementation of DNA-based screening and subsequent clinical management.