Number of variants located in the X chromosome retained after each filter step.

Abbreviations: SNPs, single nucleotide variants/polymorphisms; INDELs, insertions and deletions; MAF, minor allele frequency; GoNL, Genome of the Netherlands project database, 498 unrelated Dutch individuals; EA, NHLBI Exome Sequencing Project database, 4,300 European-American unrelated individuals; 1000G, 1000 Genomes Project, 2,500 individuals from about 25 populations around the world.