Neurodegeneration with brain iron accumulation (NBIA) is an umbrella term for 12 disease subtypes, all characterized by the build-up of iron within the brain. One of these subtypes is beta-propeller protein-associated neurodegeneration (BPAN) caused by a mutation in the WDR45 gene. This protein is involved in the autophagy pathway; the exact mechanism is still unknown. Other NBIA subtypes are PKAN, CoPAN, and FAHN. PKAN and CoPAN are involved in Coenzyme A synthesis within mitochondria and FAHN is found in myelin synthesis. Dysfunctioning of these pathways leads to a phenotype characterized by developmental delay and intellectual disabilities. Nevertheless, the exact relation between mutation and phenotype remains unknown.