Next generation sequencing - Tools and issues for human health

Since the complete sequencing of the first human genome in 2003 using the Sanger method, high-throughput sequencing technologies, grouped together under the acronym NGS (Next Generation Sequencing), have continued to evolve. Second-generation sequencers, which generate huge quantities of data at low cost and in record time, are gradually being replaced by third- and fourth-generation sequencers. These innovative machines enable the sequencing of very large DNA fragments and herald a real breakthrough. They open up new perspectives in both research and hospital settings. As a result, the traditional approach to medicine has changed significantly, and is gradually moving towards a more personalized approach. Among the many applications of NGS, the resequencing of the human genome aims to decipher each patient's genetic heritage in order to optimize the diagnosis and treatment of certain diseases. This article describes the sequencing platforms that have been most widely used since 2014. Three applications of sequencing in the healthcare field will then be discussed. The first will present the "France médecine génomique" plan, in which several human genomes will be sequenced to determine a detailed mapping of the genome. The aim of this program is to improve the diagnosis and treatment of diseases. The second application, called "metagenomics", will study the bacterial families present in our bodies. Studies have shown a link between the type of bacteria present and their association with a given disease (diabetes, obesity, cancer, etc.). The final application concerns sequencing at single-cell level. Thanks to advances in technology, it is now possible to analyze a single cell and thus identify the cell types of a tumor. However, next-generation sequencing still has its limitations, such as the sheer volume of data generated. How can storage methods be adapted to these developments? What are the current methods for analyzing and interpreting all this information? Last but not least, the accessibility of human genome sequences raises a number of ethical questions concerning the use of the data. Should we provide information on pathologies for which no treatment is available? What are the risks involved? How can this data be protected? What degree of confidentiality should be maintained? These are just some of the questions raised by NGS, to which we need to find answers.