Search

Purpose: Families living with mitochondrial diseases (MD) often endure prolonged diagnostic journeys and invasive testing, yet many remain without a molecular diagnosis. The Australian Genomics Mitochondrial Flagship, comprising clinicians, diagnostic, and research scientists, conducted a prospective national study to identify the diagnostic utility of singleton genomic sequencing using blood samples., Methods: A total of 140 children and adults living with suspected MD were recruited using modified Nijmegen criteria (MNC) and randomized to either exome + mitochondrial DNA (mtDNA) sequencing or genome sequencing., Results: Diagnostic yield was 55% (n = 77) with variants in nuclear (n = 37) and mtDNA (n = 18) MD genes, as well as phenocopy genes (n = 22). A nuclear gene etiology was identified in 77% of diagnoses, irrespective of disease onset. Diagnostic rates were higher in pediatric-onset (71%) than adult-onset (31%) cases and comparable in children with non-European (78%) vs European (67%) ancestry. For children, higher MNC scores correlated with increased diagnostic yield and fewer diagnoses in phenocopy genes. Additionally, 3 adult patients had a mtDNA deletion discovered in skeletal muscle that was not initially identified in blood., Conclusion: Genomic sequencing from blood can simplify the diagnostic pathway for individuals living with suspected MD, especially those with childhood onset diseases and high MNC scores., Competing Interests: Conflict of Interest John Christodoulou is an approved pathology provider for Victorian Clinical Genetics Services., (Copyright © 2024 American College of Medical Genetics and Genomics. Published by Elsevier Inc. All rights reserved.)

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., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Australian Genomics is a national collaborative partnership of more than 100 organizations piloting a whole-of-system approach to integrating genomics into healthcare, based on federation principles. In the first five years of operation, Australian Genomics has evaluated the outcomes of genomic testing in more than 5,200 individuals across 19 rare disease and cancer flagship studies. Comprehensive analyses of the health economic, policy, ethical, legal, implementation and workforce implications of incorporating genomics in the Australian context have informed evidence-based change in policy and practice, resulting in national government funding and equity of access for a range of genomic tests. Simultaneously, Australian Genomics has built national skills, infrastructure, policy, and data resources to enable effective data sharing to drive discovery research and support improvements in clinical genomic delivery., Competing Interests: Declaration of interests R.L.W. is the Chair of the Medical Services Advisory Committee; the views in this paper are not representing those of the Commonwealth of Australia. I.E.S. has served on scientific advisory boards for BioMarin, Chiesi, Eisai, Encoded Therapeutics, GlaxoSmithKline, Knopp Biosciences, Nutricia, Rogcon, Takeda Pharmaceuticals, UCB, and Xenon Pharmaceuticals; has received speaker honoraria from GlaxoSmithKline, UCB, BioMarin, Biocodex, Chiesi, Liva Nova, Nutricia, Zuellig Pharma, and Eisai; has received funding for travel from UCB, Biocodex, GlaxoSmithKline, Biomarin, and Eisai; has served as an investigator for Anavex Life Sciences, Cerecin Inc, Cerevel Therapeutics, Eisai, Encoded Therapeutics, EpiMinder Inc, Epygenyx, ES-Therapeutics, GW Pharma, Marinus, Neurocrine BioSciences, Ovid Therapeutics, Takeda Pharmaceuticals, UCB, Ultragenyx, Xenon Pharmaceuticals, Zogenix, and Zynerba; and has consulted for Care Beyond Diagnosis, Epilepsy Consortium, Atheneum Partners, Ovid Therapeutics, UCB, Zynerba Pharmaceuticals, BioMarin, Encoded Therapeutics, and Biohaven Pharmaceuticals; and is a Non-Executive Director of Bellberry Ltd and a Director of the Australian Academy of Health and Medical Sciences and the Australian Council of Learned Academies Limited. She may accrue future revenue on pending patent WO61/010,176 (filed: 2008): Therapeutic Compound; has a patent for SCN1A testing held by Bionomics Inc and licensed to various diagnostic companies; and has a patent molecular diagnostic/theranostic target for benign familial infantile epilepsy (BFIE) (PRRT2) 2,011,904,493 & 2,012,900,190 and PCT/AU2012/001,321 (TECH ID:2012-009)., (Copyright © 2023 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)