Fig. 1

Allelic discrimination plots of SNPs of RFX2, BCAS3 and KCNQ1. a Representative plots for rs12236871 of RFX3. Well-separated clusters representing each genotype (G/G, G/A and A/A) can be observed. b Representative plots of rs11653176 of BCAS3. Well-separated clusters are clearly visible, representing each genotype (T/T, T/C and C/C). c Representative plots of rs179785 of KCNQ1. Computer auto analysis divided these plots into three groups (G/G, A/G and A/A). However, the plots seemed to be clustered into four groups (labeled as Groups 1 to 4). We therefore employed direct sequencing to confirm the genotypes. As a result, a 12-bp deletion variant of KCNQ1 (rs200562977) was identified in several samples of all of four groups, and rs179785 of KCNQ1 is located at the last nucleotide of this deletion variant (also see Figs. 2 and 3). Therefore, because it is difficult to genotype rs179785 using the TaqMan method, we performed the subsequent genotyping of rs179785 and rs200562977 by direct sequencing