In contrast, in a fetal kidney from a patient who died in utero at 22 weeks of gestation with transient Bartter’s syndrome caused by a truncating mutation (c.1038C→G; p.Y346*), LC3B immunoreactivity was abundantly detected primarily in the epithelia of medullary collecting ducts (co-labeled with cytokeratin) and to a lesser extent in the surrounding interstitial cells (Figure 3). The gene discussed is MAP1LC3B; the disease is Bartter syndrome.