Fig. 1.

Comparison of the number of variants imputed and predicted imputation accuracy stratified by minor allele frequency using the hybrid vs. HRC reference panels. The number of single-nucleotide variants or SNVs (indels were excluded from the hybrid for a fair comparison with HRC) in a the CFTR region (chr7:117,110,017–117,318,718; hg19) and b chromosome 7 minus the CFTR region. Multi-allelic variants are counted as one occurrence. r² is the predicted imputation accuracy. The hybrid reference improves the number of SNVs imputed over the HRC for both the CFTR region and the full chromosome 7 for variants with MAF ≥ 1%