In the past several years, single-molecule sequencing platforms, such as those by Pacific Biosciences and Oxford Nanopore Technologies, have become available to researchers and are currently being tested for clinical applications. They offer exceptionally long reads that permit direct sequencing through regions of the genome inaccessible or difficult to analyze by short-read platforms. This includes disease-causing long repetitive elements, extreme GC content regions, and complex gene loci. Similarly, these platforms enable structural variation characterization at previously unparalleled resolution and direct detection of epigenetic marks in native DNA. Here, we review how these technologies are opening up new clinical avenues that…
The wide implementation of next-generation sequencing (NGS) technologies has revolutionized the field of medical genetics. However, the short read lengths of currently used sequencing approaches pose a limitation for identification of structural variants, sequencing repetitive regions, phasing alleles and distinguishing highly homologous genomic regions. These limitations may significantly contribute to the diagnostic gap in patients with genetic disorders who have undergone standard NGS, like whole exome or even genome sequencing. Now, the emerging long-read sequencing (LRS) technologies may offer improvements in the characterization of genetic variation and regions that are difficult to assess with the currently prevailing NGS approaches. LRS…
Ali Bashir from the Icahn Institute for Genomics and Multiscale Biology at Mount Sinai describes a tool to detect tandem repeats (PACMonSTR), which he believes are dramatically underrepresented in the human genome reference but that can be discovered with PacBio sequencing. In a collaboration with Cold Spring Harbor Laboratory and Cornell, Bashir and his team generated shotgun, whole-genome sequence data from human genomic DNA using PacBio sequencing. Their goal was to find structural variation features that are not present in the existing reference. He shows numerous examples wherein the long PacBio reads were able to resolve inversions in the sample,…
In this Webinar, we will give an introduction to Pacific Biosciences’ single molecule, real-time (SMRT) sequencing. After showing how the system works, we will discuss the main features of the technology with an emphasis on the difference between systematic error and random error and how SMRT sequencing produces better consensus accuracy than other systems. Following this, we will discuss several ground-breaking discoveries in medical science that were made possible by the longs reads and high accuracy of SMRT Sequencing.