WDR45 and neurodegeneration with brain iron accumulation 5: The causative gene of SENDA/BPAN is WDR45 coding WIPI4, which is known to play an important role in autophagy.2,4 Autophagy is an essential intracellular degradation system that is involved in quality control and amino acid supply in cells, as unnecessary intracellular proteins or organelles are degraded and removed by lysosome.