CRS1 is an alias for the gene, Twist family bHLH transcription factor 1, in humans. Other names include: Twist-related protein 1; bHLHa38; H-twist; Class A basic helix-loop-helix protein 38; Saethre-Chotzen syndrome; BPES2; BPES3; CRS; CSO; SCS; TWIST. The encoded protein has an amino acid length of 202 and a mass of 21.0 kDa. Other isoforms may exist. This gene shares homology with other species, including: Zebrafish.