Rates and Classification of Variants of Uncertain Significance in Hereditary Disease Genetic Testing.

Importance: Variants of uncertain significance (VUSs) are rampant in clinical genetic testing, frustrating clinicians, patients, and laboratories because the uncertainty hinders diagnoses and clinical management. A comprehensive assessment of VUSs across many disease genes is needed to guide efforts to reduce uncertainty. Objective: To describe the sources, gene distribution, and population-level attributes of VUSs and to evaluate the impact of the different types of evidence used to reclassify them. Design, Setting, and Participants: This cohort study used germline DNA variant data from individuals referred by clinicians for diagnostic genetic testing for hereditary disorders. Participants included individuals for whom gene panel testing was conducted between September 9, 2014, and September 7, 2022. Data were analyzed from September 1, 2022, to April 1, 2023. Main Outcomes and Measures: The outcomes of interest were VUS rates (stratified by age; clinician-reported race, ethnicity, and ancestry groups; types of gene panels; and variant attributes), percentage of VUSs reclassified as benign or likely benign vs pathogenic or likely pathogenic, and enrichment of evidence types used for reclassifying VUSs. Results: The study cohort included 1 689 845 individuals ranging in age from 0 to 89 years at time of testing (median age, 50 years), with 1 203 210 (71.2%) female individuals. There were 39 150 Ashkenazi Jewish individuals (2.3%), 64 730 Asian individuals (3.8%), 126 739 Black individuals (7.5%), 5539 French Canadian individuals (0.3%), 169 714 Hispanic individuals (10.0%), 5058 Native American individuals (0.3%), 2696 Pacific Islander individuals (0.2%), 4842 Sephardic Jewish individuals (0.3%), and 974 383 White individuals (57.7%). Among all individuals tested, 692 227 (41.0%) had at least 1 VUS and 535 385 (31.7%) had only VUS results. The number of VUSs per individual increased as more genes were tested, and most VUSs were missense changes (86.6%). More VUSs were observed per sequenced gene in individuals who were not from a European White population, in middle-aged and older adults, and in individuals who underwent testing for disorders with incomplete penetrance. Of 37 699 unique VUSs that were reclassified, 30 239 (80.2%) were ultimately categorized as benign or likely benign. A mean (SD) of 30.7 (20.0) months elapsed for VUSs to be reclassified to benign or likely benign, and a mean (SD) of 22.4 (18.9) months elapsed for VUSs to be reclassified to pathogenic or likely pathogenic. Clinical evidence contributed most to reclassification. Conclusions and Relevance: This cohort study of approximately 1.6 million individuals highlighted the need for better methods for interpreting missense variants, increased availability of clinical and experimental evidence for variant classification, and more diverse representation of race, ethnicity, and ancestry groups in genomic databases. Data from this study could provide a sound basis for understanding the sources and resolution of VUSs and navigating appropriate next steps in patient care.

Applications of artificial intelligence in clinical laboratory genomics.

The transition from analog to digital technologies in clinical laboratory genomics is ushering in an era of "big data" in ways that will exceed human capacity to rapidly and reproducibly analyze those data using conventional approaches. Accurately evaluating complex molecular data to facilitate timely diagnosis and management of genomic disorders will require supportive artificial intelligence methods. These are already being introduced into clinical laboratory genomics to identify variants in DNA sequencing data, predict the effects of DNA variants on protein structure and function to inform clinical interpretation of pathogenicity, link phenotype ontologies to genetic variants identified through exome or genome sequencing to help clinicians reach diagnostic answers faster, correlate genomic data with tumor staging and treatment approaches, utilize natural language processing to identify critical published medical literature during analysis of genomic data, and use interactive chatbots to identify individuals who qualify for genetic testing or to provide pre-test and post-test education. With careful and ethical development and validation of artificial intelligence for clinical laboratory genomics, these advances are expected to significantly enhance the abilities of geneticists to translate complex data into clearly synthesized information for clinicians to use in managing the care of their patients at scale.

Noncoding variants alter GATA2 expression in rhombomere 4 motor neurons and cause dominant hereditary congenital facial paresis.

Hereditary congenital facial paresis type 1 (HCFP1) is an autosomal dominant disorder of absent or limited facial movement that maps to chromosome 3q21-q22 and is hypothesized to result from facial branchial motor neuron (FBMN) maldevelopment. In the present study, we report that HCFP1 results from heterozygous duplications within a neuron-specific GATA2 regulatory region that includes two enhancers and one silencer, and from noncoding single-nucleotide variants (SNVs) within the silencer. Some SNVs impair binding of NR2F1 to the silencer in vitro and in vivo and attenuate in vivo enhancer reporter expression in FBMNs. Gata2 and its effector Gata3 are essential for inner-ear efferent neuron (IEE) but not FBMN development. A humanized HCFP1 mouse model extends Gata2 expression, favors the formation of IEEs over FBMNs and is rescued by conditional loss of Gata3. These findings highlight the importance of temporal gene regulation in development and of noncoding variation in rare mendelian disease.

TUBB3 Arg262His causes a recognizable syndrome including CFEOM3, facial palsy, joint contractures, and early-onset peripheral neuropathy.

Microtubules are formed from heterodimers of alpha- and beta-tubulin, each of which has multiple isoforms encoded by separate genes. Pathogenic missense variants in multiple different tubulin isoforms cause brain malformations. Missense mutations in TUBB3, which encodes the neuron-specific beta-tubulin isotype, can cause congenital fibrosis of the extraocular muscles type 3 (CFEOM3) and/or malformations of cortical development, with distinct genotype-phenotype correlations. Here, we report fourteen individuals from thirteen unrelated families, each of whom harbors the identical NM_006086.4 (TUBB3):c.785G>A (p.Arg262His) variant resulting in a phenotype we refer to as the TUBB3 R262H syndrome. The affected individuals present at birth with ptosis, ophthalmoplegia, exotropia, facial weakness, facial dysmorphisms, and, in most cases, distal congenital joint contractures, and subsequently develop intellectual disabilities, gait disorders with proximal joint contractures, Kallmann syndrome (hypogonadotropic hypogonadism and anosmia), and a progressive peripheral neuropathy during the first decade of life. Subsets may also have vocal cord paralysis, auditory dysfunction, cyclic vomiting, and/or tachycardia at rest. All fourteen subjects share a recognizable set of brain malformations, including hypoplasia of the corpus callosum and anterior commissure, basal ganglia malformations, absent olfactory bulbs and sulci, and subtle cerebellar malformations. While similar, individuals with the TUBB3 R262H syndrome can be distinguished from individuals with the TUBB3 E410K syndrome by the presence of congenital and acquired joint contractures, an earlier onset peripheral neuropathy, impaired gait, and basal ganglia malformations.

A systematic literature review of disclosure practices and reported outcomes for medically actionable genomic secondary findings.

PURPOSE: Secondary findings (SFs) are present in 1-4% of individuals undergoing genome/exome sequencing. A review of how SFs are disclosed and what outcomes result from their receipt is urgent and timely. METHODS: We conducted a systematic literature review of SF disclosure practices and outcomes after receipt including cascade testing, family and provider communication, and health-care actions. Of the 1,184 nonduplicate records screened we summarize findings from 27 included research articles describing SF disclosure practices, outcomes after receipt, or both. RESULTS: The included articles reported 709 unique SF index recipients/families. Referrals and/or recommendations were provided 647 SF recipients and outcome data were available for 236. At least one recommended evaluation was reported for 146 SF recipients; 16 reports of treatment or prophylactic surgery were identified. We found substantial variations in how the constructs of interest were defined and described. CONCLUSION: Variation in how SF disclosure and outcomes were described limited our ability to compare findings. We conclude the literature provided limited insight into how the American College of Medical Genetics and Genomics (ACMG) guidelines have been translated into precision health outcomes for SF recipients. Robust studies of SF recipients are needed and should be prioritized for future research.

Differentiating Moebius syndrome and other congenital facial weakness disorders with electrodiagnostic studies.

INTRODUCTION: Congenital facial weakness (CFW) can result from facial nerve paresis with or without other cranial nerve and systemic involvement, or generalized neuropathic and myopathic disorders. Moebius syndrome is one type of CFW. In this study we explored the utility of electrodiagnostic studies (EDx) in the evaluation of individuals with CFW. METHODS: Forty-three subjects enrolled prospectively into a dedicated clinical protocol and had EDx evaluations, including blink reflex and facial and peripheral nerve conduction studies, with optional needle electromyography. RESULTS: MBS and hereditary congenital facial paresis (HCFP) subjects had low-amplitude cranial nerve 7 responses without other neuropathic or myopathic findings. Carriers of specific pathogenic variants in TUBB3 had, in addition, a generalized sensorimotor axonal polyneuropathy with demyelinating features. Myopathic findings were detected in individuals with Carey-Fineman-Ziter syndrome, myotonic dystrophy, other undefined myopathies, or CFW with arthrogryposis, ophthalmoplegia, and other system involvement. DISCUSSION: EDx in CFW subjects can assist in characterizing the underlying pathogenesis, as well as guide diagnosis and genetic counseling.

Brain phenotyping in Moebius syndrome and other congenital facial weakness disorders by diffusion MRI morphometry.

In this study, we used a novel imaging technique, DTI (diffusion tensor imaging)-driven tensor-based morphometry, to investigate brain anatomy in subjects diagnosed with Moebius syndrome (n = 21), other congenital facial weakness disorders (n = 9) and healthy controls (n = 15). First, we selected a subgroup of subjects who satisfied the minimum diagnostic criteria for Moebius syndrome with only mild additional neurological findings. Compared to controls, in this cohort, we found a small region of highly significant volumetric reduction in the paramedian pontine reticular formation and the medial longitudinal fasciculus, important structures for the initiation and coordination of conjugate horizontal gaze. Subsequently, we tested if volume measurements from this region could help differentiate individual subjects of the different cohorts that were included in our study. We found that this region allowed discriminating Moebius syndrome subjects from congenital facial weakness disorders and healthy controls with high sensitivity (94%) and specificity (89%). Interestingly, this region was normal in congenital facial weakness subjects with oculomotor deficits of myopathic origin, who would have been classified as Moebius on the basis of purely clinical diagnostic criteria, indicating a potential role for diffusion MRI morphometry for differential diagnosis in this condition. When the entire Moebius syndrome cohort was compared to healthy controls, in addition to this 'landmark' region, other areas of significantly reduced volume in the brainstem emerged, including the location of the nuclei and fibres of cranial nerve VI (abducens nerve), and fibres of cranial nerve VII (facial nerve), and a more rostral portion of the medial longitudinal fasciculus. The high sensitivity and specificity of DTI-driven tensor-based morphometry in reliably detecting very small areas of volumetric abnormality found in this study suggest broader applications of this analysis in personalized medicine to detect hypoplasia or atrophy of small pathways and/or brainstem nuclei in other neurological disorders.

Using the diffusion of innovations model to guide participant engagement in the genomics era.

Exome and genome sequencing (EGS) are increasingly the genetic testing modalities of choice among researchers owing to their ready availability, low cost, and large data output. Recruitment of larger, more diverse cohorts into long-term studies with extensive data collection is fundamental to the success of EGS research and to the widespread benefit of genomic medicine to various populations. Effective engagement will be critical to meeting this demand. The Diffusion of Innovation (DOI) model provides a framework for how new technologies are adopted in communities, including antecedents of an individual's decision to adopt the technology, how the technology's attributes influence its acceptability, the predictors of sustained use of that technology, and its diffusion through society. We apply the DOI model to frame participant engagement in EGS research and to guide the proposal of potential strategies that aim to overcome forecasted challenges. Finally, we suggest a variety of ways genetic counselors can apply their skills and training to the development and implementation of these strategies.

Preliminary validation of a consumer-oriented colorectal cancer risk assessment tool compatible with the US Surgeon General's My Family Health Portrait.

PURPOSE: This study examines the analytic validity of a software tool designed to provide individuals with risk assessments for colorectal cancer based on personal health and family history information. The software is compatible with the US Surgeon General's My Family Health Portrait (MFHP). METHODS: An algorithm for risk assessment was created using accepted colorectal risk assessment guidelines and programmed into a software tool (MFHP). Risk assessments derived from 150 pedigrees using the MFHP tool were compared with "gold standard" risk assessments developed by three expert cancer genetic counselors. RESULTS: Genetic counselor risk assessments showed substantial, but not perfect, agreement. MFHP risk assessments for colorectal cancer yielded a sensitivity for colorectal cancer risk of 81% (95% confidence interval: 54-96%) and specificity of 90% (95% confidence interval: 83-94%), as compared with genetic counselor pedigree review. The positive predictive value for risk for MFHP was 48% (95% confidence interval: 29-68%), whereas the negative predictive value was 98% (95% confidence interval: 93-99%). Agreement between MFHP and genetic counselor pedigree review was moderate (κ = 0.54). CONCLUSION: The analytic validity of the MFHP colorectal cancer risk assessment software is similar to those of other types of screening tools used in primary care. Future investigations should explore the clinical validity and utility of the software in diverse population groups.Genet Med 17 9, 753-756.

Research participants' attitudes towards the confidentiality of genomic sequence information.

Respecting the confidentiality of personal data contributed to genomic studies is an important issue for researchers using genomic sequencing in humans. Although most studies adhere to rules of confidentiality, there are different conceptions of confidentiality and why it is important. The resulting ambiguity obscures what is at stake when making tradeoffs between data protection and other goals in research, such as transparency, reciprocity, and public benefit. Few studies have examined why participants in genomic research care about how their information is used. To explore this topic, we conducted semi-structured phone interviews with 30 participants in two National Institutes of Health research protocols using genomic sequencing. Our results show that research participants value confidentiality as a form of control over information about themselves. To the individuals we interviewed, control was valued as a safeguard against discrimination in a climate of uncertainty about future uses of individual genome data. Attitudes towards data sharing were related to the goals of research and details of participants' personal lives. Expectations of confidentiality, trust in researchers, and a desire to advance science were common reasons for willingness to share identifiable data with investigators. Nearly, all participants were comfortable sharing personal data that had been de-identified. These findings suggest that views about confidentiality and data sharing are highly nuanced and are related to the perceived benefits of joining a research study.

A genetic counselor's guide to using next-generation sequencing in clinical practice.

Advances in next-generation sequencing (NGS) and rapid reductions in cost have increased the use of such technologies in research and clinical practice. However, many barriers exist to translating NGS for routine clinical use, including issues related to the interpretation of results, and the potential to find results that are secondary or incidental to the specific application of NGS. Nonetheless, NGS has become sufficiently affordable to be offered by several clinical laboratories, and increasingly it is becoming an attractive and viable option for clinicians and patients. This article reviews current NGS technologies, highlighting the information genetic counselors need to know to make informed-decisions about utilizing NGS in the clinic, and underscoring the impact of this new testing modality on the practice of genetic counseling.

Stem cell research and therapy: the position of the National Society of Genetic Counselors.

Stem cells' regenerative capabilities present a unique opportunity to treat human illness and injury. In 2003, the National Society of Genetic Counselors (NSGC) issued a position statement supporting stem cell use in research settings. Almost a decade later, in response to legislative and technological developments within the field of stem cell science, NSGC convened a task force to revisit and update its statement on stem cell research. In doing so, the Task Force developed a new statement reaffirming NSGC's support for stem cell research and endorsed continued stem cell therapy development. NSGC recognizes that the unique potential of stem cell therapy to treat human disease and injury can be realized only through research on a diverse array of stem cell lines drawn from multiple sources, including embryonic, cord blood, and adult cells. NSGC supports the use of stem cells in research and clinical settings when practices adhere to defined ethical and legal guidelines. Available stem cell lines should reflect our genetically diverse population, and donor recruitment should be without discrimination or coercion and include a thorough and dynamic informed consent process.

Noninvasive prenatal testing/noninvasive prenatal diagnosis: the position of the National Society of Genetic Counselors.

The 1997 discovery of free fetal DNA in maternal plasma launched clinical researchers' efforts to establish a reliable method for non-invasive prenatal testing for fetal genetic conditions. Various methods, including, but not limited to, massively parallel sequencing (MPS) and selective analysis of cell-free fetal DNA in maternal plasma, have recently been developed as highly sensitive and specific noninvasive screening tools for common fetal chromosome aneuploidies. Incorporating these new noninvasive technologies into clinical practice will impact the current prenatal screening paradigm for fetal aneuploidy, in which genetic counseling plays an integral role. The National Society of Genetic Counselors (NSGC) currently supports Noninvasive Prenatal Testing/Noninvasive Prenatal Diagnosis (NIPT/NIPD) as an option for patients whose pregnancies are considered to be at an increased risk for certain chromosome abnormalities. NSGC urges that NIPT/NIPD only be offered in the context of informed consent, education, and counseling by a qualified provider, such as a certified genetic counselor. Patients whose NIPT/NIPD results are abnormal, or who have other factors suggestive of a chromosome abnormality, should receive genetic counseling and be given the option of standard confirmatory diagnostic testing.

Intentions to receive individual results from whole-genome sequencing among participants in the ClinSeq study.

Genome sequencing has been rapidly integrated into clinical research and is currently marketed to health-care practitioners and consumers alike. The volume of sequencing data generated for a single individual and the wide range of findings from whole-genome sequencing raise critical questions about the return of results and their potential value for end-users. We conducted a mixed-methods study of 311 sequential participants in the NIH ClinSeq study to assess general preferences and specific attitudes toward learning results. We tested how these variables predicted intentions to receive results within four categories of findings ranging from medically actionable to variants of unknown significance. Two hundred and ninety-four participants indicated a preference to learn their genome sequencing results. Most often, participants cited disease prevention as their reason, including intention to change their lifestyle behaviors. Participants held positive attitudes, strongly perceived social norms and strong intentions to learn results, although there were significant mean differences among four categories of findings (P<0.01). Attitudes and social norms for medically actionable and carrier results were most similar and rated the highest. Participants distinguished among the types and quality of information they may receive, despite strong intentions to learn all results presented. These intentions were motivated by confidence in their ability to use the information to prevent future disease and a belief in the value of even uninterpretable information. It behooves investigators to facilitate participants' desire to learn a range of information from genomic sequencing while promoting realistic expectations for its clinical and personal utility.

Approaches to informed consent for hypothesis-testing and hypothesis-generating clinical genomics research.

BACKGROUND: Massively-parallel sequencing (MPS) technologies create challenges for informed consent of research participants given the enormous scale of the data and the wide range of potential results. DISCUSSION: We propose that the consent process in these studies be based on whether they use MPS to test a hypothesis or to generate hypotheses. To demonstrate the differences in these approaches to informed consent, we describe the consent processes for two MPS studies. The purpose of our hypothesis-testing study is to elucidate the etiology of rare phenotypes using MPS. The purpose of our hypothesis-generating study is to test the feasibility of using MPS to generate clinical hypotheses, and to approach the return of results as an experimental manipulation. Issues to consider in both designs include: volume and nature of the potential results, primary versus secondary results, return of individual results, duty to warn, length of interaction, target population, and privacy and confidentiality. SUMMARY: The categorization of MPS studies as hypothesis-testing versus hypothesis-generating can help to clarify the issue of so-called incidental or secondary results for the consent process, and aid the communication of the research goals to study participants.

Genomic inheritances: disclosing individual research results from whole-exome sequencing to deceased participants' relatives.

Whole-genome analysis and whole-exome analysis generate many more clinically actionable findings than traditional targeted genetic analysis. These findings may be relevant to research participants themselves as well as for members of their families. Though researchers performing genomic analyses are likely to find medically significant genetic variations for nearly every research participant, what they will find for any given participant is unpredictable. The ubiquity and diversity of these findings complicate questions about disclosing individual genetic test results. We outline an approach for disclosing a select range of genetic results to the relatives of research participants who have died, developed in response to relatives' requests during a pilot study of large-scale medical genetic sequencing. We also argue that studies that disclose individual research results to participants should, at a minimum, passively disclose individual results to deceased participants' relatives.

Secondary variants in individuals undergoing exome sequencing: screening of 572 individuals identifies high-penetrance mutations in cancer-susceptibility genes.

Genome- and exome-sequencing costs are continuing to fall, and many individuals are undergoing these assessments as research participants and patients. The issue of secondary (so-called incidental) findings in exome analysis is controversial, and data are needed on methods of detection and their frequency. We piloted secondary variant detection by analyzing exomes for mutations in cancer-susceptibility syndromes in subjects ascertained for atherosclerosis phenotypes. We performed exome sequencing on 572 ClinSeq participants, and in 37 genes, we interpreted variants that cause high-penetrance cancer syndromes by using an algorithm that filtered results on the basis of mutation type, quality, and frequency and that filtered mutation-database entries on the basis of defined categories of causation. We identified 454 sequence variants that differed from the human reference. Exclusions were made on the basis of sequence quality (26 variants) and high frequency in the cohort (77 variants) or dbSNP (17 variants), leaving 334 variants of potential clinical importance. These were further filtered on the basis of curation of literature reports. Seven participants, four of whom were of Ashkenazi Jewish descent and three of whom did not meet family-history-based referral criteria, had deleterious BRCA1 or BRCA2 mutations. One participant had a deleterious SDHC mutation, which causes paragangliomas. Exome sequencing, coupled with multidisciplinary interpretation, detected clinically important mutations in cancer-susceptibility genes; four of such mutations were in individuals without a significant family history of disease. We conclude that secondary variants of high clinical importance will be detected at an appreciable frequency in exomes, and we suggest that priority be given to the development of more efficient modes of interpretation with trials in larger patient groups.

Motivators for participation in a whole-genome sequencing study: implications for translational genomics research.

The promise of personalized medicine depends on the ability to integrate genetic sequencing information into disease risk assessment for individuals. As genomic sequencing technology enters the realm of clinical care, its scale necessitates answers to key social and behavioral research questions about the complexities of understanding, communicating, and ultimately using sequence information to improve health. Our study captured the motivations and expectations of research participants who consented to participate in a research protocol, ClinSeq, which offers to return a subset of the data generated through high-throughput sequencing. We present findings from an exploratory study of 322 participants, most of whom identified themselves as white, non-Hispanic, and coming from higher socio-economic groups. Participants aged 45-65 years answered open-ended questions about the reasons they consented to ClinSeq and about what they anticipated would come of genomic sequencing. Two main reasons for participating were as follows: a conviction to altruism in promoting research, and a desire to learn more about genetic factors that contribute to one's own health risk. Overall, participants expected genomic research to help improve understanding of disease causes and treatments. Our findings offer a first glimpse into the motivations and expectations of individuals seeking their own genomic information, and provide initial insights into the value these early adopters of technology place on information generated by high-throughput sequencing studies.

FOS expression in blood as a LDL-independent marker of statin treatment.

OBJECTIVES: The expression of FOS, a gene critical for monocyte and macrophage function, can be inhibited by statins through the disruption of a cholesterol-independent signaling pathway. In this pilot study, we hypothesized that blood FOS mRNA levels will be sensitive to statin treatment independent of LDL cholesterol levels. METHODS: Three cohorts at increased risk of or with cardiovascular disease (CVD) were studied. Blood FOS mRNA levels were measured before and after statin treatment or in patients under stable treatment. RESULTS: Statin treatment for three months significantly reduced blood FOS mRNA and LDL cholesterol levels. However, in subjects with similar LDL levels achieved by different doses of long term statin treatment, there was an inverse relationship between statin dose and FOS expression. CONCLUSIONS: FOS mRNA levels appear to be a sensitive marker of statin treatment that is dissociated from cholesterol levels.

Validation of My Family Health Portrait for six common heritable conditions.

PURPOSE: To assess the ability of My Family Health Portrait to accurately collect family history for six common heritable disorders. BACKGROUND: Family history is useful to assess disease risk but is not widely used. We compared the pedigree from My Family Health Portrait, an online tool for collection of family history, to a pedigree supplemented by a genetics professional. METHODS: One hundred fifty volunteers collected their family histories using My Family Health Portrait. A genetic counselor interviewed the volunteers to validate the entries and add diagnoses, as needed. The content and the affection assignments of the pedigrees were compared. The pedigrees were entered into Family Healthware to assess risks for the diseases. RESULTS: The sensitivity of My Family Health Portrait varied among the six diseases (67-100%) compared to the supplemented pedigree. The specificities ranged from 92 to 100%. When the pedigrees were used to generate risk scores, My Family Health Portrait yielded identical risks to the supplemented pedigree for 94-99% of the volunteers for diabetes and colon, breast, and ovarian cancer. The agreement was lower for coronary artery disease (68%) and stroke (83%). CONCLUSIONS: These data support the validity of My Family Health Portrait pedigrees for four common conditions--diabetes and colon, breast, and ovarian cancer. The tool performed less well for coronary artery disease and stroke. We recommend that the tool be improved to better capture information for these two common conditions.