Mutations in ZFYVE19, which encodes a protein involved in division of cells and in regulation of the primary cilium (an incompletely understood structure in many but not all cells), that abolish ZFYVE19 protein expression underlie a form of bile-duct and liver disease for which children may require liver transplantation.  This was not known before.  Manifestations of ZFYVE19 disease outside the hepatobiliary system, or in adults, perhaps with partial expression or partial function of the protein, now can be studied, and affected families can be helped to understand what to expect for their children with severe bile-duct and liver ZFYVE19 disease. (By Dr. Wei-Sha Luan, https://jmg.bmj.com/content/early/2020/07/31/jmedgenet-2019-106706 )