ASTN2 and neurodevelopmental disorder: The linked 9q33.1–33.2 region contain five candidate genes from the immune system that participate in synaptic processes and have been previously associated with neurodevelopmental disorders, ASTN2, BRINP1, C5, TLR4 and TRIM32. ASTN2 (Astrotactine 2) and BRINP1 (Bone Morphogenetic Protein/Retinoic Acid-inducible Neural specific Protein) encode proteins from the Membrane Attack Complex Perforin (MACPF) family, highly expressed in the developing brain (reviewed in29).