In a study published in Science Advances, a team from the Garvan Institute of Medical Research, Australia, has described how their method using nanopore sequencing technology has the potential to reduce the 'diagnostic odyssey' for people with rare neurological and neuromuscular disease. A new DNA sequencing-based test method developed by a team led by Ira Deveson, Head of Genomics Technologies at the Garvan Institute of Medical Research, and collaborators, has been shown to have the potential to screen for more than 50 genetic neurological and neuromuscular diseases. In research, this new workflow accurately identifies diseases caused by unusually long, repetitive DNA sequences in a person's genes, known as short tandem repeat (STR) expansion disorders.

Current genetic screening for these disorders can involve multiple tests, such as muscle or nerve biopsies, and take much longer, sometimes years of investigation to reach an answer. The STR repeat expansions typically span a longer region of DNA than the read lengths generated by short-read sequencing technology. To overcome this, the research teams used Oxford Nanopore technology, which can read fragments of any length and can be programmed to target specific regions of DNA.

During a recent presentation [available here] on this work Ira Deveson described long-read nanopore technology as 'the ideal tool'. He went on to discuss the future potential for nanopore sequencing to 'solve the problem in one step' by reading STRs end-to-end in single long reads. In the published study the team describe how they achieved accurate molecular characterisation of all known neuropathogenic STRs in a single workflow, as well as DNA methylation, with no additional library preparation or costs.

Once validated using nanopore sequencing to target specific regions of interest may also be useful to guide personalised selection of medications. This research demonstrates the potential for nanopore sequencing in disease characterisation and the study discusses how this could be a powerful approach for STR gene discovery for previously unsolved cases as well.