The imprinting cluster on human chromosome 11p15.5. The distal breakpoint cluster region (BWSCR1) is indicated. Breakpoints within BWSCR1 disrupt KvLQT1. Solid red symbols indicate allelic silencing; green/white symbols indicate allelic transcription. The imprinting status of the INS (insulin) gene has not been defined in humans. Further details are included in the text.