To confirm and extend SNP genotypes, iN cultures were harvested for bulk RNAseq analysis. To identify isoforms, RNAseq data identified only the longer KCNJ6 isoform ENST00000609713 (Fig. 1B), which includes a 3′ exon of 18,112 nucleotides primarily consisting of 3′UTR. We identified 19 additional 3′UTR SNPs linked with the initial three (Supplementary Table 1; red lines in Fig. 1B), constituting a haplotype of 22 variants (synonymous and noncoding) within the expressed isoform of KCNJ6 mRNA, all in a region of linkage disequilibrium (LD; Supplementary Fig. 1C). There are no nonsynonymous variants, therefore, this haplotype is predicted to alter KCNJ6 mRNA stability, translation, or other post-transcriptional processes.
