Points to Consider in the Clinical Use of NGS Panels for Mitochondrial Disease: An Analysis of Gene Inclusion and Consent Forms
Mitochondrial next generation sequencing (NGS) panels offer single-step analysis of the numerous nuclear genes involved in the structure, function, and maintenance of mitochondria. However, the complexities of mitochondrial biology and genetics raise points for consideration in clinical use of these tests. To understand the current status of mitochondrial genetic testing, we assessed the gene offerings and consent forms of mitochondrial NGS panels available from seven US-based clinical laboratories. The NGS panels varied markedly in number of genes (101–1204 genes), and the proportion of genes causing “classic” mitochondrial diseases and their phenocopies ranged widely between labs (18 %–94 % of panel contents). All panels included genes not associated with classic mitochondrial diseases (6 %–28 % of panel contents), including genes causing adult-onset neurodegenerative disorders, cancer predisposition, and other genetic syndromes or inborn errors of metabolism. Five of the panels included genes that are not listed in OMIM to be associated with a disease phenotype (5 %–49 % of panel contents). None of the consent documents reviewed had options for patient preference regarding receipt of incidental findings. These findings raise points of discussion applicable to mitochondrial diagnostics, but also to the larger arenas of exome and genome sequencing, including the need to consider the boundaries between clinical and research testing, the necessity of appropriate informed consent, and the responsibilities of clinical laboratories and clinicians. Based on these findings, we recommend careful evaluation by laboratories of the genes offered on NGS panels, clear communication of the predicted phenotypes, and revised consent forms to allow patients to make choices about receiving incidental findings. We hope that our analysis and recommendations will help to maximize the considerable clinical utility of NGS panels for the diagnosis of mitochondrial disease.
KeywordsMitochondrial disease diagnostics Clinical gene panel Mitochondrial NGS panel Informed consent
Many thanks to the clinical laboratories, whose hard work provides valuable diagnostic testing options for patients with rare genetic diseases. Thanks to Monisha Shah for her assistance with statistics.
Julia Platt, Rachel Cox, and Gregory Enns declare that they have no conflict of interest. No animal or human studies were carried out by the authors for this article.
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