(A) Schematic of the human chromosomal segment containing SOX9 and its flanking upstream and downstream domains. The coding genes that are SOX9’s neighbors are shown (KCNJ2 and SLC39A11), as well as non-coding genes (RefSeq and GeneBank, CCDS, Rfam and tRNA, as listed on the UCSC genome browser). (B) Schematic of the domains upstream of SOX9 that are prone to chromosomal alterations causing PRS, ACD and CD disease. The shaded background illustrates that other domains are also subject to disease-causing alterations. (C) Location of tissue-specific enhancers identified upstream and downstream of SOX9. The position of each enhancer is indicated with an arrow. The main domain of activity of each enhancer is indicated and represented with colors.