Keeping up with the next generation: massively parallel sequencing in clinical diagnostics.

The speed, accuracy, efficiency, and cost-effectiveness of DNA sequencing have been improving continuously since the initial derivation of the technique in the mid-1970s. With the advent of massively parallel sequencing technologies, DNA sequencing costs have been dramatically reduced. No longer is it unthinkable to sequence hundreds or even thousands of genes in a single individual with a suspected genetic disease or complex disease predisposition. Along with the benefits offered by these technologies come a number of challenges that must be addressed before wide-scale sequencing becomes accepted medical practice. Molecular diagnosticians will need to become comfortable with, and gain confidence in, these new platforms, which are based on radically different technologies compared to the standard DNA sequencers in routine use today. Experience will determine whether these instruments are best applied to sequencing versus resequencing. Perhaps most importantly, along with increasing read lengths inevitably comes increased ascertainment of novel sequence variants of uncertain clinical significance, the postanalytical aspects of which could bog down the entire field. But despite these obstacles, and as a direct result of the promises these sequencing advances present, it will likely not be long before next-generation sequencing begins to make an impact in molecular medicine. In this review, technical issues are discussed, in addition to the practical considerations that will need to be addressed as advances push toward personal genome sequencing.