There are four human WIPIβ-propellor proteins, all members of the PROPPIN family. In autophagy they bind PI3P at the phagophore to recruit other interactors acting as a scaffold during autophagosome biogenesis. Specifically, WIPI2b binds ATG16L1 and WIPI4 ATG2. WIPI2 and WIPI4 have been shown to interact with one another but the nature and function of this interaction is unknown. We have begun characterisation of this interaction to understand the functional protein complex at the phagophore and the consequence of this interaction. Mutations in the WDR45 gene, encoding WIPI4, cause the neurodegenerative disease BPAN. The molecular mechanism of how such mutations cause disease is not clear, specifically if they cause impairment to WIPI4’s function in autophagy. Mutations in the WIPI2 gene have also been linked to neurodevelopmental disorders, with milder phenotypes than BPAN. We are developing disease models from patient derived neurons to be used to study the molecular mechanisms of WIPI2 and WIPI4 interactions and how disease mutations affect neuronal autophagy.