• Aamira J Huq, Bryony Thompson, Mark F Bennett, Adam Bournazos, Shobhana Bommireddipalli, Alexandra Gorelik, Joshua Schultz, Adrienne Sexton, Rebecca Purvis, Kirsty West, Megan Cotter, Giulia Valente, Andrew Hughes, Moeen Riaz, Maie Walsh, Sarah Farrand, Samantha M Loi, Trevor Kilpatrick, Amy Brodtmann, David Darby, Dhamidhu Eratne, Mark Walterfang, Martin Bruce Delatycki, Elsdon Storey, Michael Fahey, Sandra Cooper, Paul Lacaze, Colin L Masters, Dennis Velakoulis, Melanie Bahlo, Paul A James, and Ingrid Winship.
• Department of Genomic Medicine, Royal Melbourne Hospital City Campus, Parkville, Victoria, Australia Aamira.huq@mh.org.au.
• J. Neurol. Neurosurg. Psychiatr. 2022 Jul 29.

BackgroundIn the clinical setting, identification of the genetic cause in patients with early-onset dementia (EOD) is challenging due to multiple types of genetic tests required to arrive at a diagnosis. Whole-genome sequencing (WGS) has the potential to serve as a single diagnostic platform, due to its superior ability to detect common, rare and structural genetic variation.MethodsWGS analysis was performed in 50 patients with EOD. Point mutations, small insertions/deletions, as well as structural variants (SVs) and short tandem repeats (STRs), were analysed. An Alzheimer's disease (AD)-related polygenic risk score (PRS) was calculated in patients with AD.ResultsClinical genetic diagnosis was achieved in 7 of 50 (14%) of the patients, with a further 8 patients (16%) found to have established risk factors which may have contributed to their EOD. Two pathogenic variants were identified through SV analysis. No expanded STRs were found in this study cohort, but a blinded analysis with a positive control identified a C9orf72 expansion accurately. Approximately 37% (7 of 19) of patients with AD had a PRS equivalent to >90th percentile risk.DiscussionWGS acts as a single genetic test to identify different types of clinically relevant genetic variations in patients with EOD. WGS, if used as a first-line clinical diagnostic test, has the potential to increase the diagnostic yield and reduce time to diagnosis for EOD.© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.

9 keywords...

hide…