WDR45 and neurodegeneration with brain iron accumulation: Beta‐propeller protein‐associated neurodegeneration (BPAN, OMIM 300894), a subtype of neurodegeneration with brain iron accumulation (NBIA), is an X‐linked neurodegenerative disorder caused by mutations in WDR45, the gene encoding a member of WIPI family, WDR45 (also called WIPI4).