I just read a helpful paper on pathway analysis and interactome reconstruction: Tieri, P., Fuente, A. D., Termanini, A., & Franceschi, C. (2011). Integrating Omics Data for Signaling Pathways, Interactome Reconstruction, and Functional Analysis. In Bioinformatics for Omics Data, Methods in Molecular Biology, vol.

In a previous post I linked to gcol as a quick and intuitive alternative to awk. I just stumbled across yet another set of handy text file manipulation utilities from the creators of the BEAGLE software for GWAS data imputation and analysis.

PLINK/SEQ is an open source C/C++ library for analyzing large-scale genome sequencing data. The library can be accessed via the pseq command line tool, or through an R interface. The project is developed independently of PLINK but it's syntax will be familiar to PLINK users. PLINK/SEQ boasts an impressive feature set for a project still in the beta testing phase.

**** UPDATE, May 15 2014 ***** The functions described here have now been wrapped into an R package. View the updated blog post or see the online package vignette for how to install and use. If you'd still like to use the old code described here, you can access this at version 0.0.0 on GitHub.

I'm working on a project using next-gen sequencing to fine-map a genetic association in a gene region. Now that I've sequenced the region in a small sample, I'm picking SNPs to genotype in a larger sample. When designing the genotyping assay the lab will need flanking sequence. This is easy to get for SNPs in dbSNP, but what about novel SNPs?

Hansong Wang, our biostats professor here at the Hawaii Cancer Center, generously gave me some R code that goes through a SNP annotation file (i.e. a mapfile) and selects SNPs that are at least a certain specified distance apart. You might want to do this if you're picking a subset of SNPs for PCA, for instance.

The *ABEL suite of R packages and software for genetic analysis has grown substantially since the appearance of GenABEL and the previously mentioned ProbABEL R packages. There are now a handful of useful R packages and other software utilities facilitating genome-wide association studies, analysis of imputed data, meta-analysis, efficient data storage, prediction, parallelization, and mixed model methods.

Obtaining the probability that zero, one, or two alleles are shared identical by descent (IBD) is useful for many reasons in a GWAS analysis. A while back I showed you how to visualize sample relatedness using R and ggplot2, which requires IBD estimates. Using plink --genome uses IBS and allele frequencies to infer IBD.

While writing my thesis I came across this nice review by Rita Cantor, Kenneth Lange, and Janet Sinsheimer at UCLA, "Prioritizing GWAS Results: A Review of Statistical Methods and Recommendations for Their Application." Skip the introduction unless you're new to GWAS, in which case you'll probably want to start with this more recent review by Teri Manolio.

Will Bush and I just heard that our paper "Multivariate Analysis of Regulatory SNPs: Empowering Personal Genomics by Considering Cis-Epistasis and Heterogeneity" was accepted for publication and a talk at the Personal Genomics session of the 2011 Pacific Symposium in Biocomputing.