Sawona Biswas

Performance of ACMG-AMP Variant-Interpretation Guidelines among Nine Laboratories in the Clinical Sequencing Exploratory Research Consortium

Evaluating the pathogenicity of a variant is challenging given the plethora of types of genetic evidence that laboratories consider. Deciding how to weigh each type of evidence is difficult, and standards have been needed. In 2015, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) published guidelines for the assessment of variants in genes associated with Mendelian diseases. Nine molecular diagnostic laboratories involved in the Clinical Sequencing Exploratory Research (CSER) consortium piloted these guidelines on 99 variants spanning all categories (pathogenic, likely pathogenic, uncertain significance, likely benign, and benign). Nine variants were distributed to all laboratories, and the remaining 90 were evaluated by three laboratories. The laboratories classified each variant by using both the laboratorys own method and the ACMG-AMP criteria. The agreement between the two methods used within laboratories was high (K-alpha = 0.91) with 79% concordance. However, there was only 34% concordance for either classification system across laboratories. After consensus discussions and detailed review of the ACMG-AMP criteria, concordance increased to 71%. Causes of initial discordance in ACMG-AMP classifications were identified, and recommendations on clarification and increased specification of the ACMG-AMP criteria were made. In summary, although an initial pilot of the ACMG-AMP guidelines did not lead to increased concordance in variant interpretation, comparing variant interpretations to identify differences and having a common framework to facilitate resolution of those differences were beneficial for improving agreement, allowing iterative movement toward increased reporting consistency for variants in genes associated with monogenic disease.

Erratum: Performance of ACMG-AMP Variant-Interpretation Guidelines among Nine Laboratories in the Clinical Sequencing Exploratory Research Consortium (American Journal of Human Genetics (2016) 98(6) (1067–1076) (S0002929716300593) (10.1016/j.ajhg.2016.03.024))

Laura M. Amendola,1,16 Gail P. Jarvik,1,16,* Michael C. Leo,2 Heather M. McLaughlin,3 Yassmine Akkari,4 Michelle D. Amaral,5 Jonathan S. Berg,6 Sawona Biswas,7 Kevin M. Bowling,5 Laura K. Conlin,7 Greg M. Cooper,5 Michael O. Dorschner,8 Matthew C. Dulik,9 Arezou A. Ghazani,10 Rajarshi Ghosh,11 Robert C. Green,3,12,15 Ragan Hart,1 Carrie Horton,13 Jennifer J. Johnston,14 Matthew S. Lebo,3,12 Aleksandar Milosavljevic,11 Jeffrey Ou,1 Christine M. Pak,4 Ronak Y. Patel,11 Sumit Punj,4 Carolyn Sue Richards,4 Joseph Salama,1 Natasha T. Strande,6 Yaping Yang,11 Sharon E. Plon,11 Leslie G. Biesecker,14 and Heidi L. Rehm3,12,15,*

Illustrative case studies in the return of exome and genome sequencing results

Whole genome and exome sequencing tests are increasingly being ordered in clinical practice, creating a need for research exploring the return of results from these tests. A goal of the Clinical Sequencing and Exploratory Research (CSER) consortium is to gain experience with this process to develop best practice recommendations for offering exome and genome testing and returning results. Genetic counselors in the CSER consortium have an integral role in the return of results from these genomic sequencing tests and have gained valuable insight. We present seven emerging themes related to return of exome and genome sequencing results accompanied by case descriptions illustrating important lessons learned, counseling challenges specific to these tests and considerations for future research and practice.

How do providers discuss the results of pediatric exome sequencing with families

AIM This study provides preliminary data on the process and content of returning results from exome sequencing offered to children through one of the Clinical Sequencing Exploratory Research (CSER) projects. MATERIALS & METHODS We recorded 25 sessions where providers returned diagnostic and secondary sequencing results to families. Data interpretation utilized inductive thematic analysis. RESULTS Typically, providers followed a results report and discussed diagnostic findings using technical genomic and sequencing concepts. We identified four provider processes for returning results: teaching genetic concepts; assessing family response; personalizing findings; and strengthening patient-provider relationships. CONCLUSION Sessions should reflect family interest in medical management and next steps, and minimize detailed genomic concepts. As the scope and complexity of sequencing increase, the traditional information-laden counseling model requires revision.

Why Patients Decline Genomic Sequencing Studies: Experiences from the CSER Consortium

Clinical and research settings are increasingly incorporating genomic sequencing (GS) technologies. Previous research has explored reasons for declining genetic testing and participation in genetic studies; however, there is a dearth of literature regarding why potential participants decline participation in GS research, and if any of these reasons are unique to GS. This knowledge is essential to promote informed decision-making and identify potential barriers to research participation and clinical implementation. We aggregated data from seven sites across the National Institutes of Health’s Clinical Sequencing Exploratory Research (CSER) consortium on each project’s procedures for recruitment, and rates of and reasons for decline. Data were analyzed using descriptive statistics. The decline rate for enrollment at the seven CSER sites ranged from 12 to 64% (median 28%) and varied based on age and disease status. Projects differed in their protocols for approaching potential participants and obtaining informed consent. Reasons for declining GS research were reported for 1088 potential participants. Commonly cited reasons were similar to those reported for clinical single gene testing and non-GS genetic research. The most frequently cited reason for decline was study logistics (35%); thus, addressing logistical barriers to enrollment may positively impact GS study recruitment. Privacy and discrimination concerns were cited by 13% of decliners, highlighting the need for researchers and providers to focus educational efforts in this area. The potential psychological burden of pursuing and receiving results from GS and not wanting to receive secondary findings, a concern specific to GS, have been cited as concerns in the literature. A minority of potential participants cited psychological impact (8%) or not wanting to receive secondary findings (2%) as reasons for decline, suggesting that these concerns were not major barriers to participation in these GS studies. Further research is necessary to explore the impact, if any, of different participant groups or study protocols on rates of decline for GS studies. Future studies exploring GS implementation should consider using standardized collection methods to examine reasons for decline in larger populations and more diverse healthcare settings.

Anticipated responses of early adopter genetic specialists and nongenetic specialists to unsolicited genomic secondary findings

PurposeSecondary findings from genomic sequencing are becoming more common. We compared how health-care providers with and without specialized genetics training anticipated responding to different types of secondary findings.MethodsProviders with genomic sequencing experience reviewed five secondary-findings reports and reported attitudes and potential clinical follow-up. Analyses compared genetic specialists and physicians without specialized genetics training, and examined how responses varied by secondary finding.ResultsGenetic specialists scored higher than other providers on four-point scales assessing understandings of reports (3.89 vs. 3.42, p = 0.0002), and lower on scales assessing reporting obligations (2.60 vs. 3.51, p < 0.0001) and burdens of responding (1.73 vs. 2.70, p < 0.0001). Nearly all attitudes differed between findings, although genetic specialists were more likely to assert that laboratories had no obligations when findings had less-established actionability (p < 0.0001 in interaction tests). The importance of reviewing personal and family histories, documenting findings, learning more about the variant, and recommending familial discussions also varied according to finding (all p < 0.0001).ConclusionGenetic specialists felt better prepared to respond to secondary findings than providers without specialized genetics training, but perceived fewer obligations for laboratories to report them, and the two groups anticipated similar clinical responses. Findings may inform development of targeted education and support.

Utility and limitations of exome sequencing in the molecular diagnosis of pediatric inherited platelet disorders

Inherited platelet disorders (IPD) are a heterogeneous group of rare disorders that affect platelet number and function and often predispose to other significant medical complications. In spite of the identification of over 50 IPD disease‐associated genes, a molecular diagnosis is only identified in a minority (10%) of affected patients without a clinically suspected etiology. We studied a cohort of 21 pediatric patients with suspected IPDs by exome sequencing (ES) to: (1) examine the performance of the exome test for IPD genes, (2) determine if this exome‐wide diagnostic test provided a higher diagnostic yield than has been previously reported, (3) to evaluate the frequency of variants of uncertain significance identified, and (4) to identify candidate variants for functional evaluation in patients with an uncertain or negative diagnosis. We established a high priority gene list of 53 genes, evaluated exome capture kit performance, and determined the coverage for these genes and disease‐related variants. We identified likely disease causing variants in 5 of the 21 probands (23.8%) and variants of uncertain significance in 52% of patients studied. In conclusion, ES has the potential to molecularly diagnose causes of IPD, and to identify candidate genes for functional evaluation. Robust exome sequencing also requires that coverage of genes known to be associated with clinical findings of interest need to be carefully examined and supplemented if necessary. Clinicians who undertake ES should understand the limitations of the test and the full significance of results that may be returned.

AUDIOME: a tiered exome sequencing–based comprehensive gene panel for the diagnosis of heterogeneous nonsyndromic sensorineural hearing loss

PurposeHereditary hearing loss is highly heterogeneous. To keep up with rapidly emerging disease-causing genes, we developed the AUDIOME test for nonsyndromic hearing loss (NSHL) using an exome sequencing (ES) platform and targeted analysis for the curated genes.MethodsA tiered strategy was implemented for this test. Tier 1 includes combined Sanger and targeted deletion analyses of the two most common NSHL genes and two mitochondrial genes. Nondiagnostic tier 1 cases are subjected to ES and array followed by targeted analysis of the remaining AUDIOME genes.ResultsES resulted in good coverage of the selected genes with 98.24% of targeted bases at >15 ×. A fill-in strategy was developed for the poorly covered regions, which generally fell within GC-rich or highly homologous regions. Prospective testing of 33 patients with NSHL revealed a diagnosis in 11 (33%) and a possible diagnosis in 8 cases (24.2%). Among those, 10 individuals had variants in tier 1 genes. The ES data in the remaining nondiagnostic cases are readily available for further analysis.ConclusionThe tiered and ES-based test provides an efficient and cost-effective diagnostic strategy for NSHL, with the potential to reflex to full exome to identify causal changes outside of the AUDIOME test.

Clinical providers’ experiences with returning results from genomic sequencing: an interview study

BackgroundCurrent medical practice includes the application of genomic sequencing (GS) in clinical and research settings. Despite expanded use of this technology, the process of disclosure of genomic results to patients and research participants has not been thoroughly examined and there are no established best practices.MethodsWe conducted semi-structured interviews with 21 genetic and non-genetic clinicians returning results of GS as part of the NIH funded Clinical Sequencing Exploratory Research (CSER) Consortium projects. Interviews focused on the logistics of sessions, participant/patient reactions and factors influencing them, how the sessions changed with experience, and resources and training recommended to return genomic results.ResultsThe length of preparation and disclosure sessions varied depending on the type and number of results and their implications. Internal and external databases, online resources and result review meetings were used to prepare. Respondents reported that participants’ reactions were variable and ranged from enthusiasm and relief to confusion and disappointment. Factors influencing reactions were types of results, expectations and health status. A recurrent challenge was managing inflated expectations about GS. Other challenges included returning multiple, unanticipated and/or uncertain results and navigating a rare diagnosis. Methods to address these challenges included traditional genetic counseling techniques and modifying practice over time in order to provide anticipatory guidance and modulate expectations. Respondents made recommendations to improve access to genomic resources and genetic referrals to prepare future providers as the uptake of GS increases in both genetic and non-genetic settings.ConclusionsThese findings indicate that returning genomic results is similar to return of results in traditional genetic testing but is magnified by the additional complexity and potential uncertainty of the results. Managing patient expectations, initially identified in studies of informed consent, remains an ongoing challenge and highlights the need to address this issue throughout the testing process. The results of this study will help to guide future providers in the disclosure of genomic results and highlight educational needs and resources necessary to prepare providers. Future research on the patient experience, understanding and follow-up of recommendations is needed to more fully understand the disclosure process.

Approaches to carrier testing and results disclosure in translational genomics research: The clinical sequencing exploratory research consortium experience

Clinical genome and exome sequencing (CGES) is primarily used to address specific clinical concerns by detecting risk of future disease, clarifying diagnosis, or directing treatment. Additionally, CGES makes possible the disclosure of autosomal recessive and X‐linked carrier results as additional secondary findings, and research about the impact of carrier results disclosure in this context is needed.