Title
A quality control algorithm for filtering SNPs in genome-wide association studies.
Abstract
The quality control (QC) filtering of single nucleotide polymorphisms (SNPs) is an important step in genome-wide association studies to minimize potential false findings. SNP QC commonly uses expert-guided filters based on QC variables [e.g. Hardy-Weinberg equilibrium, missing proportion (MSP) and minor allele frequency (MAF)] to remove SNPs with insufficient genotyping quality. The rationale of the expert filters is sensible and concrete, but its implementation requires arbitrary thresholds and does not jointly consider all QC features.We propose an algorithm that is based on principal component analysis and clustering analysis to identify low-quality SNPs. The method minimizes the use of arbitrary cutoff values, allows a collective consideration of the QC features and provides conditional thresholds contingent on other QC variables (e.g. different MSP thresholds for different MAFs). We apply our method to the seven studies from the Wellcome Trust Case Control Consortium and the major depressive disorder study from the Genetic Association Information Network. We measured the performance of our method compared to the expert filters based on the following criteria: (i) percentage of SNPs excluded due to low quality; (ii) inflation factor of the test statistics (lambda); (iii) number of false associations found in the filtered dataset; and (iv) number of true associations missed in the filtered dataset. The results suggest that with the same or fewer SNPs excluded, the proposed algorithm tends to give a similar or lower value of lambda, a reduced number of false associations, and retains all true associations.The algorithm is available at http://www4.stat.ncsu.edu/jytzeng/software.php
Year
DOI
Venue
2010
10.1093/bioinformatics/btq272
Bioinformatics
Keywords
Field
DocType
qc variable,fewer snps,false association,snp qc,conditional thresholds contingent,true association,filtered dataset,insufficient genotyping quality,low-quality snps,genome-wide association study,quality control algorithm,qc feature,algorithms,genome wide association study,quality control,genome
Data mining,Computer science,Cutoff,Genome-wide association study,Genetic association,Single-nucleotide polymorphism,Minor allele frequency,Bioinformatics,Cluster analysis,Principal component analysis,Statistical hypothesis testing
Journal
Volume
Issue
ISSN
26
14
1367-4811
Citations 
PageRank 
References 
1
0.37
3
Authors
3
Name
Order
Citations
PageRank
Monnat Pongpanich110.37
patrick f sullivan216522.87
Jung-Ying Tzeng322.11