A protocol uses single-molecule sequencing to measure C9orf72 repeat expansions
Original source
Single-Molecule Sequencing of the C9orf72 Repeat Expansion in Patient iPSCs. (opens in a new tab)Compass summarised this from the study's abstract.
Related topics
Researchers described a method that uses PacBio single-molecule sequencing and CRISPR/Cas9 enrichment to detect and size C9orf72 repeat expansions without copying the DNA. In patient-derived induced pluripotent stem cells, the method consistently measured expansions, including repeats numbering in the thousands.
Why this matters
More accurate measurement of these expansions could support research using patient cells and may be applicable to DNA from blood or other tissues. This protocol does not change treatment and is not presented as a clinical test validation.
Limitations and context
The report describes a laboratory protocol tested on patient-derived induced pluripotent stem cells, not a clinical study. It requires high-molecular-weight DNA and specific PacBio sequencing instruments, and the authors state that it is not compatible with the Revio platform. Its performance in routine diagnostic settings would still need to be established.