Criteria for reporting incidental findings in clinical exome sequencing - a focus group study on professional practices and perspectives in Belgian genetic centres

Computational Tools to Assist in Analyzing Effects of the SERPINA1 Gene Variation on Alpha-1 Antitrypsin (AAT)

In the rapidly advancing field of bioinformatics, the development and application of computational tools to predict the effects of single nucleotide variants (SNVs) are shedding light on the molecular mechanisms underlying disorders. Also, they hold promise for guiding therapeutic interventions and personalized medicine strategies in the future. A comprehensive understanding of the impact of SNVs in the SERPINA1 gene on alpha-1 antitrypsin (AAT) protein structure and function requires integrating bioinformatic approaches. Here, we provide a guide for clinicians to navigate through the field of computational analyses which can be applied to describe a novel genetic variant. Predicting the clinical significance of SERPINA1 variation allows clinicians to tailor treatment options for individuals with alpha-1 antitrypsin deficiency (AATD) and related conditions, ultimately improving the patient's outcome and quality of life. This paper explores the various bioinformatic methodologies and cutting-edge approaches dedicated to the assessment of molecular variants of genes and their product proteins using SERPINA1 and AAT as an example.

Exploring uncertainties regarding unsolicited findings in genetic testing

OBJECTIVES

Non-normative uncertainty (uncertainty about empirical facts) and normative uncertainty (uncertainty about moral values or beliefs) regarding unsolicited findings (UFs) might play an important role in clinical genetics. Identifying normative uncertainty is of special interest since it might guide towards novel directions for counseling practice. This study aims to gain insight into the role of non-normative and normative uncertainty regarding UFs, as expressed by counselees and counselors.

METHODS

We performed a secondary qualitative analysis of interviews with counselees (n = 20) and counselors (n = 20) who had been confronted with UFs. Following a deductive approach, we used Han et al.'s existing theoretical framework of uncertainty, in which we additionally incorporated normative uncertainty.

RESULTS

Major issues of non-normative uncertainty were practical and personal for counselees, whilst counselors' uncertainty pertained mainly to scientific issues. Normative uncertainty was a major theme throughout the interviews. We encountered the moral conflicts of autonomy vs. beneficence and non-maleficence and of autonomy vs. truthfulness.

CONCLUSION

Non-normative uncertainty regarding UFs highlights the need to gain more insight in their penetrance and clinical utility. This study suggests moral conflicts are a major source of feelings of uncertainty in clinical genetics.

PRACTICE IMPLICATIONS

Exploring counselees' non-normative uncertainties and normative conflicts seems a prerequisite to optimize genetic counseling.

Challenges and Pragmatic Solutions in Pre-Test and Post-Test Genetic Counseling for Prenatal Exome Sequencing

The yield of genetic prenatal diagnosis has been notably improved by introducing whole genome chromosomal microarray (CMA) and prenatal exome sequencing (pES). However, together with increased numbers of diagnoses made, the need to manage challenging findings such as variants of unknown significance (VUS) and incidental findings (IF) also increased. We have summarized the current guidelines and recommendations and we have shown current solutions used in our tertiary center in the Netherlands. We discuss four of the most common clinical situations: fetus with normal pES results, fetus with a pathogenic finding explaining the fetal phenotype, fetus with a variant of uncertain clinical significance fitting the phenotype and fetus with a variant leading to an incidental diagnosis. Additionally, we reflect on solutions in order to facilitate genetic counseling in an NGS-era.

Reporting clinically relevant genetic variants unrelated to genomic test requests: a survey of Australian clinical laboratory policies and practices

Approaches to reporting clinically important genetic findings unrelated to the initial test request vary internationally. We sought to investigate practices regarding the management and return of these findings in Australia. Australian clinically accredited genetic testing laboratories were surveyed in 2017 and 2020 regarding their opinions on issues relating to the return of clinically important genetic findings unrelated to the initial test request. Responses were collated and analysed for 15 laboratories in 2017, and 17 laboratories in 2020. Content analysis was also performed on seven laboratory policies in 2020. Analysis showed that overall there was a lack of consensus about the terminology used to describe such findings and reporting practices across different testing contexts. A clear exception was that no laboratories were actively searching for a list of medically actionable genes (eg, American College of Medical Genetics and Genomics secondary findings gene list). Laboratory policies showed little consistency in the documentation of issues related to the handling of these findings. These findings indicate a need for Australian-specific policy guidance that covers all aspects of clinically important genetic findings unrelated to the initial test request. We present recommendations for consideration when developing laboratory policies.

Challenges Related to the Use of Next-Generation Sequencing for the Optimization of Drug Therapy

Over the last decade, next-generation sequencing (NGS) methods have become increasingly used in various areas of human genomics. In routine clinical care, their use is already implemented in oncology to profile the mutational landscape of a tumor, as well as in rare disease diagnostics. However, its utilization in pharmacogenomics is largely lacking behind. Recent population-scale genome data has revealed that human pharmacogenes carry a plethora of rare genetic variations that are not interrogated by conventional array-based profiling methods and it is estimated that these variants could explain around 30% of the genetically encoded functional pharmacogenetic variability.To interpret the impact of such variants on drug response a multitude of computational tools have been developed, but, while there have been major advancements, it remains to be shown whether their accuracy is sufficient to improve personalized pharmacogenetic recommendations in robust trials. In addition, conventional short-read sequencing methods face difficulties in the interrogation of complex pharmacogenes and high NGS test costs require stringent evaluations of cost-effectiveness to decide about reimbursement by national healthcare programs. Here, we illustrate current challenges and discuss future directions toward the clinical implementation of NGS to inform genotype-guided decision-making.

Calculating variant penetrance from family history of disease and average family size in population-scale data

BACKGROUND

Genetic penetrance is the probability of a phenotype when harbouring a particular pathogenic variant. Accurate penetrance estimates are important across biomedical fields including genetic counselling, disease research, and gene therapy. However, existing approaches for penetrance estimation require, for instance, large family pedigrees or availability of large databases of people affected and not affected by a disease.

METHODS

We present a method for penetrance estimation in autosomal dominant phenotypes. It examines the distribution of a variant among people affected (cases) and unaffected (controls) by a phenotype within population-scale data and can be operated using cases only by considering family disease history. It is validated through simulation studies and candidate variant-disease case studies.

RESULTS

Our method yields penetrance estimates which align with those obtained via existing approaches in the Parkinson's disease LRRK2 gene and pulmonary arterial hypertension BMPR2 gene case studies. In the amyotrophic lateral sclerosis case studies, examining penetrance for variants in the SOD1 and C9orf72 genes, we make novel penetrance estimates which correspond closely to understanding of the disease.

CONCLUSIONS

The present approach broadens the spectrum of traits for which reliable penetrance estimates can be obtained. It has substantial utility for facilitating the characterisation of disease risks associated with rare variants with an autosomal dominant inheritance pattern. The yielded estimates avoid any kinship-specific effects and can circumvent ascertainment biases common when sampling rare variants among control populations.

Protocolo genético en Atención Primaria para enfermedades raras: el síndrome de Wolfram como prototipo

Las enfermedades raras, pese a su baja frecuencia individual, afectan globalmente al 7% de la población, por lo que el profesional de Atención Primaria (AP) tendrá varios de estos pacientes bajo seguimiento. El 80% de estas enfermedades tienen base genética, lo que hace fundamental un asesoramiento genético adecuado. El seguimiento de pacientes con síndrome de Wolfram (SW) puede servir para diseñar un protocolo susceptible de ser utilizado en el diagnóstico y manejo de otras entidades y ser utilizado por profesionales sanitarios para dar soporte a los pacientes, contando con la participación de profesionales sanitarios e investigadores especializados en el SW, los propios pacientes y su entorno. Se desarrollan los pasos fundamentales de todo procedimiento clínico genético, en el que la AP es clave para dar soporte a estas familias y transmitir de forma comprensible la información sobre los aspectos genéticos.

Molecular Diagnostic Outcomes from 700 Cases: What Can We Learn from a Retrospective Analysis of Clinical Exome Sequencing?

Clinical exome sequencing (CES) aids in the diagnosis of rare genetic disorders. Herein, we report the molecular diagnostic yield and spectrum of genetic alterations contributing to disease in 700 pediatric cases analyzed at the Children's Hospital of Philadelphia. The overall diagnostic yield was 23%, with three cases having more than one molecular diagnosis and 2.6% having secondary/additional findings. A candidate gene finding was reported in another 8.4% of cases. The clinical indications with the highest diagnostic yield were neurodevelopmental disorders (including seizures), whereas immune- and oncology-related indications were negatively associated with molecular diagnosis. The rapid expansion of knowledge regarding the genome's role in human disease necessitates reanalysis of CES samples. To capture these new discoveries, a subset of cases (n = 240) underwent reanalysis, with an increase in diagnostic yield. We describe our experience reporting CES results in a pediatric setting, including reporting of secondary findings, reporting newly discovered genetic conditions, and revisiting negative test results. Finally, we highlight the challenges associated with implementing critical updates to the CES workflow. Although these updates are necessary, they demand an investment of time and resources from the laboratory. In summary, these data demonstrate the clinical utility of exome sequencing and reanalysis, while highlighting the critical considerations for continuous improvement of a CES test in a clinical laboratory.

The prenatal exome - a door to prenatal diagnostics?

Introduction: Prenatal exome sequencing (ES) allows parents the opportunity to obtain arapid molecular diagnosis of monogenic etiology when their fetus is found to have structural anomalies detected on prenatal ultrasound. Such information can improve antenatal and neonatal counseling, decision-making and management, and expand reproductive options in subsequent pregnancies.Areas covered: This review appraises the evidence, from acomprehensive search of bibliographic databases, for the introduction of ES into the fetal medicine care pathway when investigating congenital malformations. The perspectives of clinical geneticists, clinical scientists, fetal medicine specialists, and patients are explored in relation to the novel investigation and the benefits and challenges of its use in ongoing pregnancies with particular reference to UK medical practice.Expert opinion: ES provides agenetic diagnosis for more than 1 in 10 fetuses with structural differences on ultrasound and normal conventional tests (karyotype or chromosomal microarray) in carefully selected cases. The diagnostic rate increases for certain phenotypes and can range between 6% and 80% where conventional cytogenetics have not detected adiagnosis. Expert oversight is required to ensure that patients receive high-quality, evidence-based care and accurate counseling, supported by amultidisciplinary team familiar with the test and its implications.

Attitudes among South African university staff and students towards disclosing secondary genetic findings

The present study represents an initial step in understanding diverse academic perspectives on the disclosure of secondary findings (SFs) from genetic research conducted in Africa. Using an online survey completed by 674 university students and academic staff in South Africa, we elicited attitudes towards the return of SFs. Latent class analysis (LCA) was performed to classify sub-groups of participants according to their overall attitudes to returning SFs. We did not find substantial differences in attitudes towards the return of findings between staff and students. Overall, respondents were in favour of the return of SFs in genetics research, depending on the type. The majority of survey respondents (80%) indicated that research participants should be given the option of deciding whether to have genetic SFs returned. LCA revealed that the largest group (53%) comprised individuals with more favourable attitudes to the return of SFs in genetics research. Those with less favourable attitudes comprised only 4% of the sample. This study provides important insights that may, together with further empirical evidence, inform the development of research guidelines and policy to assist healthcare professionals and researchers.

Incidental diagnosis of mucopolysaccharidosis type I in an infant with chronic intestinal pseudoobstruction by exome sequencing

Chronic intestinal pseudoobstruction (CIPO) is a severe form of intestinal dysmotility, and patients often undergo iterative abdominal surgeries and require parenteral nutrition. Several genes are known to be responsible for this pathology, including ACTG2 (autosomal dominant) and MYH11 (autosomal recessive). We report the first case of unexpected trio medical exome sequencing diagnosis of mucopolysaccharidosis type I (MPS-I) in a patient with an early CIPO. There was no clinical suspicion of MPS-I at the time of the prescription. It allowed biochemical confirmation of MPS-I, expert clinical evaluation and early treatment. Enzyme replacement therapy (ERT) with laronidase was started at 9 months old, and hematopoietic stem cell transplantation was carried out at 10 months and a half. The patient also had a 1.7 mb heterozygous deletion in chromosomal region 16p13.11p12.3, comprising several genes, including MYH11, paternally inherited. Her father has no symptoms of CIPO or other digestive symptoms. One previous association of CIPO and MPS-I was reported in 1986. Moreover, the number of incidental findings of inherited metabolic disorders with therapeutic impact will inevitably increase as pangenomic analyses become cheaper and easily available.

Ethical values supporting the disclosure of incidental and secondary findings in clinical genomic testing: a qualitative study

BACKGROUND

Incidental findings (IFs) and secondary findings (SFs), being results that are unrelated to the diagnostic question, are the subject of an important debate in the practice of clinical genomic medicine. Arguments for reporting these results or not doing so typically relate to the principles of autonomy, non-maleficence and beneficence. However, these principles frequently conflict and are insufficient by themselves to come to a conclusion. This study investigates empirically how ethical principles are considered when actually reporting IFs or SFs and how value conflicts are weighed.

METHODS

A qualitative focus group study has been undertaken, including a multidisciplinary group of professionals from Belgian centres for medical genetics. The data were analysed thematically.

RESULTS

All eight Belgian centres participated in this study. Ethical values were frequently referred to for disclosure policies on IFs and SFs. Participants invoked respect for patient autonomy to support the disclosure of IFs and opt-out options for IFs and SFs, non-maleficence for the professional delineation of reportable IFs and opt-out options for IFs and SFs and (the particular scope of) beneficence for the mandatory reporting of actionable IFs, the delineation of reportable IFs and a current decline of actively pursued SFs. Professional assumptions about patients' genetic literacy were an important factor in the weighing of values.

CONCLUSIONS

In line with the traditional bioethical discourse, the mandatory reporting of actionable IFs might be interpreted as a "technological, soft paternalism". Restricting patients' choices might be acceptable, but then its motives should be valid and its beneficent outcomes highly plausible. Hence, the presuppositions of technological, soft paternalism - patients' inability to make informed decisions, normative rationality, the efficacy of beneficent outcomes and the delineated spectrum of beneficence - should be approached critically. Moreover, distributive justice should be considered an important value in the delineation of the current scope of the ethical debate on IFs and SFs. This study of guiding values may stimulate the debate on the ethical grounds for a solid policy on IFs and SFs internationally.