Gene organization of human ORMDL1, ORMDL2, ORMDL3, ORMDL1, ORMDL2, and Drosophila ORMDL. Exon numbers of ORMDL1 are shown above the bars. Coding exons are shown in color and their sizes (in nucleotides) are: exon 3, 181 (orange); exon 4, 152 (yellow); exon 5, 133 (green). The intron sizes in kilobases are shown in-between the bars. The numbers below the bars denote the amino-acid positions for the exon-intron boundaries, and for the end of the ORF. The dotted appearance of the bar representing exon 2 of ORMDL1 indicates that it is alternatively spliced. The structure of the two human pseudogenes is also shown. The chromosomal location of each gene or pseudogene is indicated to the right.