Should we respect parents' views about which results to return from genomic sequencing?

Genomic sequencing (GS) is now well embedded in clinical practice. However, guidelines issued by professional bodies disagree about whether unsolicited findings (UF)-i.e., disease-causing changes found in the DNA unrelated to the reason for testing-should be reported if they are identified inadvertently during data analysis. This extends to a lack of clarity regarding parents' ability to decide about receiving UF for their children. To address this, I use an ethical framework, the Zone of Parental Discretion (ZPD), to consider which UF parents should be allowed to choose (not) to receive and examine how well this assessment aligns with existing professional recommendations. Assessment of guidelines shows recommendations ranging from leaving the decision to the discretion of laboratories through to mandatory reporting for UF for childhood onset, treatable/preventable conditions. The ZPD suggests that parents' decisions should be respected, even where there is no expected benefit, provided that there is not sufficient evidence of serious harm. Using this lens, parents should be able to choose whether or not to know UF for adult-onset conditions in their children, but only insofar as there is insufficient evidence that this knowledge will cause harm or benefit. In contrast, parents should not be allowed to refuse receiving UF for childhood-onset medically actionable conditions. The ZPD is a helpful tool for assessing where it is appropriate to offer parents the choice of receiving UF for their children. This has implications for refinement of policy and laboratory reporting practices, development of consent forms, and genetic counselling practice.

How do consent forms for diagnostic high-throughput sequencing address unsolicited and secondary findings? A content analysis.

Whole exome and whole genome sequencing are increasingly being offered to patients in the clinical setting. Yet, the question of whether, and to what extent, unsolicited findings (UF) and/or secondary findings (SF) should be returned to patients remains open and little is known about how diagnostic consent forms address this issue. We systematically identified consent forms for diagnostic genomic sequencing online and used inductive content analysis to determine if and how they discuss reporting of UF and SF, and whether patients are given options regarding the return of these results. Fifty-four forms representing 38 laboratories/clinics were analyzed. A quarter of the forms did not mention UF or SF. Forms used a variety of terms to discuss UF and SF, sometimes using these interchangeably or incorrectly. Reporting policies for UF varied: 5 forms stated that UF will not be returned, 15 indicated UF may be returned, and 28 did not specify their policy. One-third indicated their laboratory returns SF. Addressing inconsistent terminology and providing sufficient information about UF/SF in consent forms will increase patient understanding and help ensure adequate informed consent.

Points to consider for laboratories reporting results from diagnostic genomic sequencing.

Although NGS technologies are well-embedded in the clinical setting for identification of genetic causes of disease, guidelines issued by professional bodies are inconsistent regarding some aspects of reporting results. Most recommendations do not give detailed guidance about whether variants of uncertain significance (VUS) should be reported by laboratory personnel to clinicians, and give conflicting messages regarding whether unsolicited findings (UF) should be reported. There are also differences both in their recommendations regarding whether actively searching for secondary findings (SF) is appropriate, and in the extent to which they address the duty (or lack thereof) to reanalyse variants when new information arises. An interdisciplinary working group considered the current guidelines, their own experiences, and data from a recent qualitative study to develop a set of points to consider for laboratories reporting results from diagnostic NGS. These points to consider fall under six categories: (i) Testing approaches and technologies used, (ii) Approaches for VUS; (iii) Approaches for reporting UF, (iv) Approaches regarding SF; (v) Reanalysis of data & re-contact; and vi) Minors. While it is unclear whether uniformity in reporting across all laboratories is desirable, we hope these points to consider will be useful to diagnostic laboratories as they develop their processes for making decisions about reporting VUS and UF from NGS in the diagnostic context.

SCARB2 mutations in progressive myoclonus epilepsy (PME) without renal failure.

OBJECTIVE: Mutations in SCARB2 were recently described as causing action myoclonus renal failure syndrome (AMRF). We hypothesized that mutations in SCARB2 might account for unsolved cases of progressive myoclonus epilepsy (PME) without renal impairment, especially those resembling Unverricht-Lundborg disease (ULD). Additionally, we searched for mutations in the PRICKLE1 gene, newly recognized as a cause of PME mimicking ULD. METHODS: We reviewed cases of PME referred for diagnosis over two decades in which a molecular diagnosis had not been reached. Patients were classified according to age of onset, clinical pattern, and associated neurological signs into "ULD-like" and "not ULD-like." After exclusion of mutations in cystatin B (CSTB), DNA was examined for sequence variation in SCARB2 and PRICKLE1. RESULTS: Of 71 cases evaluated, 41 were "ULD-like" and five had SCARB2 mutations. None of 30 "not ULD-like" cases were positive. The five patients with SCARB2 mutations had onset between 14 and 26 years of age, with no evidence of renal failure during 5.5 to 15 years of follow-up; four were followed until death. One living patient had slight proteinuria. A subset of 25 cases were sequenced for PRICKLE1 and no mutations were found. INTERPRETATION: Mutations in SCARB2 are an important cause of hitherto unsolved cases of PME resembling ULD at onset. SCARB2 should be evaluated even in the absence of renal involvement. Onset is in teenage or young adult life. Molecular diagnosis is important for counseling the patient and family, particularly as the prognosis is worse than classical ULD.

Failure to confirm association of a polymorphism in ABCB1 with multidrug-resistant epilepsy.

Alteration of ATP-binding cassette subfamily B member 1 transporter (ABCB1) can plausibly cause drug-resistant epilepsy as it influences brain penetration of drugs. The CC genotype at the ABCB1 C3435T polymorphism was reported to be associated with multidrug resistance. A replication study in 401 drug-resistant and 208 drug-responsive subjects with epilepsy showed no significant association between the CC genotype and drug-resistant epilepsy. The authors suggest the initial association may have arisen by chance.