Frequently asked questions about the clinical utility of next-generation sequencing in molecular diagnosis of human genetic diseases

Before the advent of next-generation massively parallel sequencing (MPS), Sanger sequencing for many years has been the gold standard for the identification of unknown mutations in candidate genes. However, since the introduction of high-throughput massively parallel sequencing for clinical diagnostics, the next-generation sequencing (NGS) technology has revolutionized the molecular diagnosis of human inherited disorders. This new technology provides a broad spectrum of clinically relevant features at different levels of mutation detection, cost, and turnaround time. Nevertheless, the complex technologies involved, novel analytical and bioinformatics pipelines, and the challenges of nucleotide variant interpretation are difficult topics for general clinicians to understand fully. Yet, a better grasp of these subjects is needed in order to choose the most effective diagnostic approach and to convey the complex results to their patients appropriately. This chapter describes the frequently asked questions and answers related to the clinical utility of NGS-based molecular diagnostic tests in the hope that clinicians in all medical specialties better understand what NGS technology can deliver for the molecular diagnosis of human genetic disorders.