PLXNB3 and CADDS: PLXNB3, the most characteristic HBP gene, is among seven genes on the X chromosome that can be deleted as part of the Contiguous ABCD1/DXS1375E Deletion Syndrome (CADDS; OMIM #300475), which includes severe cholestatic jaundice due to obstructed bile flow (Iwasa et al., 2013).