The candidate editing sites were determined experimentally by comparison of cDNA sequences and genomically encoded DNA from the same individual to avoid single nucleotide polymorphisms (SNPs). Two of the three editing sites found in mouse gene were found in the human transcript.
However, only the Q/R site was detected in all RNA, with the T/A site detected just once. Both sites are found within exon 1.
Q/R site
This site is found in exon 1 at position 66. Editing results in a codon change from a Glutamine codon to an Arginine codon.
T/A site
This site is also found in exon 1, at position 63. It was only detected in one genomic sample indicating that the edited residue may be an SNP. However, the secondary structure of the RNA is predicted, around the editing site, to be  highly conserved in mice and humans. This indicates that the T/A site may still be shown to be a site of A to I RNA editing. Editing at this site would result in an amino acid change from a Threonine to an Alanine.
The ECS is also predicted to be found within exon 1 at a location 5' to the editing region.