Secondary findings from next-generation sequencing: what does actionable in childhood really mean?

Purpose: We aimed to assess the definition of actionability of secondary findings in childhood, using a screening framework. Methods: For 31 disorders on the American College of Medical Genetics and Genomics SF v.2.0 list, World Health Organization screening criteria were applied to assess actionability in childhood. Results: The age of onset was variable. We categorized disorders based on the proportion of cases that presented in childhood: rare (n = 6), fewer than half the cases (n = 9), the majority of cases (n = 12), or unclear (n = 4). The age at initiation of intervention was based on the youngest age of onset reported, not evidence of the benefit of early intervention. For 15 disorders, guidelines were supported by a moderate quality of evidence for at least one recommendation. Only tuberous sclerosis complex had recommendations based on high-quality evidence. All others were based on evidence of low or very low quality. Conclusion: We propose that actionability in childhood should be based on the proportion of cases that manifest in childhood and the quality of the evidence supporting intervention recommendations. Ideally, disclosure in childhood would be limited to disorders for which a majority of cases present in childhood and for which interventions are supported by evidence of at least moderate quality (i.e., multiple endocrine neoplasia type 2, retinoblastoma, tuberous sclerosis complex, Marfan syndrome, and Wilson's disease).