Schematic representation of the GUCY2D (RetGC1) primary structure [5
]. The S248W missense mutation is located in the extracellular domain, and the R1091x truncation is located near the C-terminus,
downstream of the catalytic domain. LP = leader peptide; ECD = extracellular domain; TM = transmembrane domain; KHD = kinase
homology domain; DD = dimerization domain; CAT = catalytic domain.