NGS

Next Generation Sequencing (NGS) is an interesting technology for PGx

A nice overview of the Requirements for comprehensive pharmacogenetic genotyping platforms was published by Volker Lauschke et al. They claim that rare variants account for 30-40% of functional variability in PGx. However they argue that pre-emptive PGx should only include validated variants, and rare variants should be investigated only when the patient experience unexpected drug response.

Challenges

• Short read NGS requires a priori knowledge of likelihood of particular haplotypes. In silico haplotype estimation can e.g. be performed by Beagle.
• Variants in homologous regions are hard to capture. Notably, the genes CYP2D6 and CYP2A6 are challenging.
• HLA-typing require special software, e.g. Polysolver for whole exome sequencing (WES) or OptiType for whole genome sequencing (WGS)

Publications

Institution	Article	Comments
St. Jude Children’s Research Hospital	Comparison of Genome Sequencing and Clinical Genotyping for Pharmacogenes	WES and WGS can be used for PGx with in silico CNV calling and HLA calling
National Human Genome Research Institute	Assessing the capability of massively parallel sequencing for opportunistic pharmacogenetic screening	Suggests developing tools for PGx based on WES and WGS
University of Washington	PGRNseq: A Targeted Capture Sequencing Panel for Pharmacogenetic Research and Implementation	Targeted PGx panel with 84 genes