Quality control of genotypes using heritability estimates of gene content.

ABSTRACT.Quality control filtering of single nucleotide polymorphisms (SNP) is a key step when analyzing genomic data. Here, we present a practical method to identify poorly genotyped SNPs by detecting those for which gene content deviates from the pedigree-based expectation. This can be achieved by estimating the heritability of gene content at each marker, defined as the number of copies of a particular reference allele in a genotype of an animal (0, 1 or 2). The method uses Restricted Maximum Likelihood (REML) to estimate heritability of gene content at each SNP and also builds a likelihood ratio test statistic to test for zero error variance in genotyping. The proposed method is illustrated with a real dataset with genotypes from Illumina PorcineSNP60 chip