Blueprint Genetics is applying a powerful molecular biology approach called next-generation sequencing to analyze patients’ DNA. Changes in DNA sequence can cause errors in proteins and result in severe medical conditions. Genetic disorders include hereditary diseases that are caused by mutations originating in germ cells and presenting in all cells of an individual, and cancers that occur through sequential accumulation of genetic alterations in somatic cells that typically arise over long period of time. Determining the underlying DNA changes creates opportunities to diagnose genetic disorders, estimate prognosis and select preventive treatments. Next-generation sequencing is enabling comprehensive analysis of hundreds of clinically relevant target genes in a time frame that facilitates clinical reactions. Sequencing detects different types of mutations exchanging single nucleotides (point mutations), adding or removing nucleotides (insertions and deletions) or resulting in larger alterations in chromosomal structure. Blueprint Genetics is applying a targeted sequencing approach called oligonucleotide-selective sequencing “OS-Seq™” (Myllykangas et al 2011) that was developed in Stanford University to analyze disease-specific gene panels. With targeted sequencing it is possible to identify all mutations that have been previously linked to specific genetic disorders as well as novel variants in the disease-associated genes.