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

Background: Incidental and secondary findings (IFs and SFs) are subject to ongoing discussion as potential consequences of clinical exome sequencing (ES). International policy documents vary on the reporting of these findings. Discussion points include the practice of unintentionally identified IFs versus deliberately pursued SFs, patient opt-out possibilities and the spectrum of reportable findings. The heterogeneity of advice permits a non-standardised disclosure but research is lacking on actual reporting practices. Therefore, this study assessed national reporting practices for IFs and SFs in clinical ES and the underlying professional perspectives. Methods: A qualitative focus group study has been undertaken, including professionals from Belgian centres for medical genetics (CMGs). Data were analysed thematically. Results: All Belgian CMGs participated in this study. Data analysis resulted in six main themes, including one regarding the reporting criteria used for IFs. All CMGs currently use ES-based panel testing. They have limited experience with IFs in clinical ES and are cautious about the pursuit of SFs. Two main reporting criteria for IFs were referred to by all CMGs: the clinical significance of the IF (including pathogenicity and medical actionability) and patient-related factors (including the patient's preference to know and patient characteristics). The consensus over the importance of these criteria contrasted with their challenging interpretation and application. Points of concern included IFs' pathogenicity in non-symptomatic persons, IFs concerning variants of uncertain significance, the requirement and definition of medical actionability and patient opt-out possibilities. Finally, reporting decisions were guided by the interaction between the clinical significance of the IF and patient characteristics. This interaction questions the possible disclosure of findings with context-dependent and personal utility, such as IFs concerning a carrier status. To evaluate the IF's final relevance, a professional and case-by-case deliberation was considered essential. Conclusions: The challenging application of reporting criteria for IFs results in diversified practices and policy perspectives within Belgian CMGs. This echoes international concerns and may have consequences for effective policy recommendations

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, nonmaleficence 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 optout 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

The transcription factor FOXL2 in ovarian function and dysfunction.

The Blepharophimosis Ptosis Epicanthus-inversus Syndrome is a genetic disease characterized by complex eyelid malformations often associated with premature ovarian failure (POF). BPES is basically an autosomal dominant disease, due to mutations in the FOXL2 gene, which encodes a forkhead transcription factor. More than one hundred mutations of FOXL2 have been described to date. In agreement with the BPES phenotype, FOXL2 is expressed (though not exclusively) in the developing eyelids and in fetal and adult ovaries. Two mouse knock-out models have been produced. They recapitulate the BPES phenotype and have provided insights into the pathology. Loss-of-function mutations in FOXL2 are predicted to lead to BPES and POF, while hypomorphic mutations might lead to BPES without ovarian dysfunction. However, exceptions to the genotype-phenotype correlation have been described. To better understand the pathogenic effect of these mutations it is crucial to study the normal regulation of FOXL2 and its targets. We briefly address these aspects in this review and hope that basic research around FOXL2 will eventually lead to uncover new therapeutic avenues

Adult-onset congenital central hypoventilation syndrome due to PHOX2B mutation

Central hypoventilation in adult patients is a rare life-threatening condition characterised by the loss of automatic breathing, more pronounced during sleep. In most cases, it is secondary to a brainstem lesion or to a primary pulmonary, cardiac or neuromuscular disease. More rarely, it can be a manifestation of congenital central hypoventilation syndrome (CCHS). We here describe a 25-year-old woman with severe central hypoventilation triggered by analgesics. Genetic analysis confirmed the diagnosis of adult-onset CCHS caused by a heterozygous de novo poly-alanine repeat expansion of the PHOX2B gene. She was treated with nocturnal non-invasive ventilation. We reviewed the literature and found 21 genetically confirmed adult-onset CCHS cases. Because of the risk of deleterious respiratory complications, adult-onset CCHS is an important differential diagnosis in patients with central hypoventilation

Antisense oligonucleotide-based downregulation of the G56R pathogenic variant causing NR2E3-associated autosomal dominant retinitis pigmentosa

The recurrent missense variant in Nuclear Receptor Subfamily 2 Group E Member 3 (NR2E3), c.166G>A, p.(Gly56Arg) or G56R, underlies 1%–2% of cases with autosomal dominant retinitis pigmentosa (adRP), a frequent, genetically heterogeneous inherited retinal disease (IRD). The mutant NR2E3 protein has a presumed dominant negative effect (DNE) by competition for dimer formation with Cone-Rod Homeobox (CRX) but with abolishment of DNA binding, acting as a repressor in trans. Both the frequency and DNE of G56R make it an interesting target for allele-specific knock-down of the mutant allele using antisense oligonucleotides (AONs), an emerging therapeutic strategy for IRD. Here, we designed gapmer AONs with or without a locked nucleic acid modification at the site of the mutation, which were analyzed for potential off-target effects. Next, we overexpressed wild type (WT) or mutant NR2E3 in RPE-1 cells, followed by AON treatment. Transcript and protein levels of WT and mutant NR2E3 were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot respectively. All AONs showed a general knock-down of mutant and WT NR2E3 on RNA and protein level, showing the accessibility of the region for AON-induced knockdown. Further modifications are needed however to increase allele-specificity. In conclusion, we propose the first proof-of-concept for AON-mediated silencing of a single nucleotide variation with a dominant negative effect as a therapeutic approach for NR2E3-associated adRP