(a) IFIH1 spans 51,624bp of genomic sequence on chromosome 2q24.2 (163,123,589 - 163,175,213). Neighboring genes are also shown. (b) Position of identified variants within the genomic sequence of IFIH1. Exons are numbered within the boxes. Numbers given above the gene indicate the exon boundaries using cDNA numbering. (c) Schematic illustrating the position of protein domains and their amino acid boundaries within the IFIH1 1025 amino acid protein. CARD denotes caspase activation recruitment domain. Hel denotes helicase domains, where Hel1 and Hel2 are the two conserved core helicase domains, and Hel2i is an insertion domain that is conserved in the RIG-I like helicase family. P denotes pincer or bridge region which connects Hel2 to the C-terminal domain (CTD) involved in binding double stranded RNA.