A flow cell is a fluidics device where the DNA fragments in the sequencing library are sequenced. In the sequencing instrument, the sequencing library that has been prepared from the patient’s DNA is flushed through the sequencing flow cell. In targeted sequencing, the patient’s sample is prepared by adding sample-specific DNA adapters to the ends of the DNA fragments, capturing specific genomic regions by hybridization, and amplifying the sequencing libraries using PCR. In the context of specific phenotype-driven gene panels, a more targeted set of genes can be selected for sequencing. The process does not typically include the noncoding regions (>98.5%) of the human genome. A common, targeted sequencing approach is whole exome sequencing (WES) where specific molecular probes are used to capture DNA from the coding regions of >20,000 human genes. In general, targeted sequencing refers to all technologies where only a selected portion of the genome is sequenced. With targeted sequencing, it is possible to identify variants that have been previously linked to specific genetic disorders as well as novel variants in the disease-associated genes. NGS detects different types of variants such as nucleotide substitutions (point mutations) or the addition/deletion of nucleotides (insertions and deletions). NGS allows for the comprehensive analysis of thousands of clinically relevant target genes in a timeframe that facilitates clinical action. Identifying disease-causing variants can lead to a diagnosis, determine the patient’s prognosis, and can help select the most appropriate treatments. Many hereditary diseases are caused by DNA variants originating in germ cells and subsequently present in all cells of the human body. Changes to the DNA sequence (called variants) may be harmful and can result in severe medical conditions. Blueprint Genetics uses a powerful molecular biology approach called next-generation sequencing (NGS) to analyze patient DNA.
0 kommentar(er)
