An intersection of WGS- and array-genotyped markers which exhibited discordant calls between the two platforms was used for selection. A sliding window approach was utilized to find regions spanning no more than 500 bp (Sanger sequencing reasonable read length limit) and encompassing as many discordant variants from the selected set as possible. All primers for PCR amplification were designed using NCBI Primer-BLAST suite [7] with default parameters (except the melting temperature limits of 58–62 °C) and the human genome reference sequence for BLAST. PCR product lengths and primer lengths were manually optimized to find the most suitable unique match. Primer synthesis, amplification and Sanger sequencing was performed by Evrogen (Russia, Moscow). Sanger chromatograms were visualized and analyzed using 4Peaks software (Nucleobytes, The Netherlands) and CodonCode Aligner (CodonCode Corp., USA) with default trimming and quality filtering parameters.
