Schematic diagrams of the human NID1 and NID2 genes and their 5' CpG islands. Size of the genes and exon composition are shown in the upper parts of the schemes. In the lower parts, the 5' of the genes is enlarged and the presence of a dense region of CpG dinucleotides (a CpG island) is displayed. The CpG islands overlap with the first exons of the genes. Exons, arrowed boxes separated by thin lines; blue parts are non-coding regions, red parts are coding regions. CpG, each vertical bar represents the presence of a CpG dinucleotide. Arrows indicate the location of primers for MSP amplification (NID1 amplified region: from nt 986318 to nt 986461 of sequence NT_004836 version 17; NID2 amplified region: from nt 33535309 to nt 33535449 of sequence NT_026437, versione 11). All primers were designed on predicted bisulfite-modified nucleotide sequence (see Supplemental Figures 1 and 2).