WDR45 and neurodegeneration with brain iron accumulation 5: Indeed, a BPAN-causative mutant, c.700C > T/p.(Arg234*) (Wdr45-Rstop), as well as another mutant, c.439G > T (GVmut), with single amino acid substitution in the linker region between third and fourth β-propeller domains were hardly detected when expressed in primary cultured mouse cortical neurons, strongly suggesting that haploinsufficiency of WDR45 underlies the pathogenesis of BPAN (Fig. 4A).