May is ALS Awareness Month, and we’re hoping to help raise awareness by shining a spotlight on two deserving publications from scientists at the University of Washington and at the Mayo Clinic. In both studies, researchers used PacBio technology to sequence targeted genomic regions and to discover and characterize complex pathogenic variants associated with ALS. ALS, short for amyotrophic lateral sclerosis and commonly known as Lou Gehrig’s disease, is a progressive disease of the nervous system that causes loss of muscle control. The mean survival time for patients with ALS is just three to five years from diagnosis, and there…
We were delighted to host an educational workshop at last month’s annual meeting of the American Society of Human Genetics (ASHG), where we had the opportunity to feature talks from two customers as well as an overview of SMRT Sequencing. If you couldn’t attend, check out the videos or read the highlights below. Emily Hatas, our director of business development, kicked things off with a look at how SMRT Sequencing has evolved over the years. Compared to the first instrument we offered, the Sequel II System represents a 100-fold improvement in read length and a 10,000-fold improvement in throughput. As…
A new publication released in PLOS One from scientists at the Mayo Clinic offers a great look at our CRISPR/Cas9-based, amplification-free targeted sequencing method and its utility for accurately sizing a clinically important repeat expansion. “Amplification-free long-read sequencing of TCF4 expanded trinucleotide repeats in Fuchs Endothelial Corneal Dystrophy” comes from lead author Eric Wieben, senior author Michael Fautsch, and collaborators. This is the second group to use the amplification-free technique for this disease; the first performed their work on a PacBio RS II System, while this team used the newer Sequel System. What makes the disease such an interesting target…
Scientists in Japan report using the unique properties of SMRT Sequencing to detect a structural variant (SV) responsible for a hereditary form of epilepsy. The 4.6 kb intronic repeat insertion was found from low-coverage whole genome sequence data, leading the team to suggest that this approach could be useful for determining the genetic mechanisms behind many unexplained diseases. “Detecting a long insertion variant in SAMD12 by SMRT sequencing: implications of long-read whole-genome sequencing for repeat expansion diseases” comes from lead author Takeshi Mizuguchi, senior author Satoko Miyatake, and collaborators at Yokohama City University and the University of Occupational and Environmental Health School…
In a recent publication, scientists from the University of California, Davis, and PacBio reported results from an investigation of alternative splicing associated with a repeat expansion in the gene linked to fragile X syndrome. They used SMRT Sequencing to detect full-length isoforms (Iso-Seq analysis) associated with individuals at risk of FXTAS, an adult-onset neurodegenerative disorder. “Altered expression of the FMR1 splicing variants landscape in premutation carriers” comes from lead author Elizabeth Tseng, senior author Flora Tassone, and collaborators. Previous studies from the Tassone lab had used SMRT Sequencing to detect full-length isoforms in samples from premutation carriers (individuals with more…
Today is International Ataxia Awareness Day (IAAD), and we’re proud to be participating in this worthy cause. Ataxia is a group of rare, degenerative neurological diseases with a number of different presentations; many involve muscle tremors, loss of motor skills, and difficulty walking. As many as 150,000 people in the United States have some form of ataxia. Because there are so many different types of ataxia, one of the most important early steps for those affected is getting an accurate diagnosis. There are several hereditary ataxias, and genetic testing is increasingly useful for pinpointing the exact type affecting a patient.…
A compelling new paper from scientists at the Parkinson’s Institute and Clinical Center, Houston Methodist Research Institute, and several other organizations demonstrates the importance of fully sequencing repeat expansion regions for a clearer understanding of the underlying biology of the diseases they cause. This publication also offers a look at how CRISPR/Cas9 capture can be used in combination with SMRT Sequencing to access the expanded repetitive region at a base level resolution without any PCR bias. “Parkinson’s disease associated with pure ATXN10 repeat expansion” comes from lead authors Birgitt Schüle and Karen McFarland, senior author Tetsuo Ashizawa, and collaborators. The…